diff --git a/js/ductwork/debugger/tests/test_nativewrappers.js b/js/ductwork/debugger/tests/test_nativewrappers.js
index ccddb1e84548..094f990ae204 100644
--- a/js/ductwork/debugger/tests/test_nativewrappers.js
+++ b/js/ductwork/debugger/tests/test_nativewrappers.js
@@ -34,5 +34,5 @@ function run_test()
     g.stopMe(doc.createEvent("MouseEvent"));
   } + ")()");
 
-  dbg.removeAllDebuggees();
+  dbg.enabled = false;
 }
diff --git a/js/src/debugger/Debugger.cpp b/js/src/debugger/Debugger.cpp
index f58bd7de3bdf..d1157a96c522 100644
--- a/js/src/debugger/Debugger.cpp
+++ b/js/src/debugger/Debugger.cpp
@@ -316,7 +316,9 @@ Breakpoint::Breakpoint(Debugger* debugger, BreakpointSite* site,
 
 void Breakpoint::destroy(FreeOp* fop,
                          MayDestroySite mayDestroySite /* true */) {
-  site->dec(fop);
+  if (debugger->enabled) {
+    site->dec(fop);
+  }
   debugger->breakpoints.remove(this);
   site->breakpoints.remove(this);
   gc::Cell* cell = site->owningCellUnbarriered();
@@ -371,6 +373,7 @@ Debugger::Debugger(JSContext* cx, NativeObject* dbg)
     : object(dbg),
       debuggees(cx->zone()),
       uncaughtExceptionHook(nullptr),
+      enabled(true),
       allowUnobservedAsmJS(false),
       collectCoverageInfo(false),
       observedGCs(cx->zone()),
@@ -623,8 +626,8 @@ static bool DebuggerExists(GlobalObject* global,
 /* static */
 bool Debugger::hasLiveHook(GlobalObject* global, Hook which) {
   return DebuggerExists(global, [=](Debugger* dbg) {
-    return dbg->getHook(which);
-  });
+      return dbg->enabled && dbg->getHook(which);
+    });
 }
 
 /* static */
@@ -665,6 +668,10 @@ JSObject* Debugger::getHook(Hook hook) const {
 }
 
 bool Debugger::hasAnyLiveHooks(JSRuntime* rt) const {
+  if (!enabled) {
+    return false;
+  }
+
   // A onNewGlobalObject hook does not hold its Debugger live, so its behavior
   // is nondeterministic. This behavior is not satisfying, but it is at least
   // documented.
@@ -903,7 +910,7 @@ bool DebugAPI::slowPathOnLeaveFrame(JSContext* cx, AbstractFramePtr frame,
       Debugger* dbg = Debugger::fromChildJSObject(frameobj);
       EnterDebuggeeNoExecute nx(cx, *dbg, adjqi);
 
-      if (frameobj->isLive() && frameobj->onPopHandler()) {
+      if (dbg->enabled && frameobj->isLive() && frameobj->onPopHandler()) {
         OnPopHandler* handler = frameobj->onPopHandler();
 
         Maybe<AutoRealm> ar;
@@ -2193,7 +2200,7 @@ ResumeMode Debugger::dispatchHook(JSContext* cx, HookIsEnabledFun hookIsEnabled,
   if (GlobalObject::DebuggerVector* debuggers = global->getDebuggers()) {
     for (auto p = debuggers->begin(); p != debuggers->end(); p++) {
       Debugger* dbg = *p;
-      if (hookIsEnabled(dbg)) {
+      if (dbg->enabled && hookIsEnabled(dbg)) {
         if (!triggered.append(ObjectValue(*dbg->toJSObject()))) {
           return ResumeMode::Terminate;
         }
@@ -2214,7 +2221,7 @@ ResumeMode Debugger::dispatchHook(JSContext* cx, HookIsEnabledFun hookIsEnabled,
   for (Value* p = triggered.begin(); p != triggered.end(); p++) {
     Debugger* dbg = Debugger::fromJSObject(&p->toObject());
     EnterDebuggeeNoExecute nx(cx, *dbg, adjqi);
-    if (dbg->debuggees.has(global) && hookIsEnabled(dbg)) {
+    if (dbg->debuggees.has(global) && dbg->enabled && hookIsEnabled(dbg)) {
       ResumeMode resumeMode = fireHook(dbg);
       adjqi.runJobs();
       if (resumeMode != ResumeMode::Continue) {
@@ -2326,8 +2333,8 @@ ResumeMode DebugAPI::onTrap(JSContext* cx, MutableHandleValue vp) {
         continue;
       }
 
-      // There are two reasons we have to check whether dbg is debugging
-      // global.
+      // There are two reasons we have to check whether dbg is enabled and
+      // debugging global.
       //
       // One is just that one breakpoint handler can disable other Debuggers
       // or remove debuggees.
@@ -2336,7 +2343,8 @@ ResumeMode DebugAPI::onTrap(JSContext* cx, MutableHandleValue vp) {
       // specific global--until they are executed. Only now do we know which
       // global the script is running against.
       Debugger* dbg = bp->debugger;
-      if (dbg->debuggees.has(global)) {
+      bool hasDebuggee = dbg->enabled && dbg->debuggees.has(global);
+      if (hasDebuggee) {
         Maybe<AutoRealm> ar;
         ar.emplace(cx, dbg->object);
         EnterDebuggeeNoExecute nx(cx, *dbg, adjqi);
@@ -2635,7 +2643,7 @@ Maybe<double> DebugAPI::allocationSamplingProbability(GlobalObject* global) {
     // this is safe as long as dbgp does not escape.
     Debugger* dbgp = p->unbarrieredGet();
 
-    if (dbgp->trackingAllocationSites) {
+    if (dbgp->trackingAllocationSites && dbgp->enabled) {
       foundAnyDebuggers = true;
       probability = std::max(dbgp->allocationSamplingProbability, probability);
     }
@@ -2671,7 +2679,7 @@ bool DebugAPI::slowPathOnLogAllocationSite(JSContext* cx, HandleObject obj,
     // such that the vector gets reallocated.
     MOZ_ASSERT(dbgs.begin() == begin);
 
-    if ((*dbgp)->trackingAllocationSites &&
+    if ((*dbgp)->trackingAllocationSites && (*dbgp)->enabled &&
         !(*dbgp)->appendAllocationSite(cx, obj, frame, when)) {
       return false;
     }
@@ -2689,7 +2697,7 @@ bool Debugger::isDebuggeeUnbarriered(const Realm* realm) const {
 bool Debugger::appendAllocationSite(JSContext* cx, HandleObject obj,
                                     HandleSavedFrame frame,
                                     mozilla::TimeStamp when) {
-  MOZ_ASSERT(trackingAllocationSites);
+  MOZ_ASSERT(trackingAllocationSites && enabled);
 
   AutoRealm ar(cx, object);
   RootedObject wrappedFrame(cx, frame);
@@ -3216,21 +3224,21 @@ bool Debugger::hookObservesAllExecution(Hook which) {
 }
 
 Debugger::IsObserving Debugger::observesAllExecution() const {
-  if (!!getHook(OnEnterFrame)) {
+  if (enabled && !!getHook(OnEnterFrame)) {
     return Observing;
   }
   return NotObserving;
 }
 
 Debugger::IsObserving Debugger::observesAsmJS() const {
-  if (!allowUnobservedAsmJS) {
+  if (enabled && !allowUnobservedAsmJS) {
     return Observing;
   }
   return NotObserving;
 }
 
 Debugger::IsObserving Debugger::observesCoverage() const {
-  if (collectCoverageInfo) {
+  if (enabled && collectCoverageInfo) {
     return Observing;
   }
   return NotObserving;
@@ -3347,7 +3355,7 @@ bool DebugAPI::isObservedByDebuggerTrackingAllocations(
       // Use unbarrieredGet() to prevent triggering read barrier while
       // collecting, this is safe as long as dbg does not escape.
       Debugger* dbg = p->unbarrieredGet();
-      if (dbg->trackingAllocationSites) {
+      if (dbg->trackingAllocationSites && dbg->enabled) {
         return true;
       }
     }
@@ -3754,6 +3762,71 @@ static Debugger* Debugger_fromThisValue(JSContext* cx, const CallArgs& args,
   Debugger* dbg = Debugger_fromThisValue(cx, args, fnname); \
   if (!dbg) return false
 
+/* static */
+bool Debugger::getEnabled(JSContext* cx, unsigned argc, Value* vp) {
+  THIS_DEBUGGER(cx, argc, vp, "get enabled", args, dbg);
+  args.rval().setBoolean(dbg->enabled);
+  return true;
+}
+
+/* static */
+bool Debugger::setEnabled(JSContext* cx, unsigned argc, Value* vp) {
+  THIS_DEBUGGER(cx, argc, vp, "set enabled", args, dbg);
+  if (!args.requireAtLeast(cx, "Debugger.set enabled", 1)) {
+    return false;
+  }
+
+  bool wasEnabled = dbg->enabled;
+  dbg->enabled = ToBoolean(args[0]);
+
+  if (wasEnabled != dbg->enabled) {
+    if (dbg->trackingAllocationSites) {
+      if (wasEnabled) {
+        dbg->removeAllocationsTrackingForAllDebuggees();
+      } else {
+        if (!dbg->addAllocationsTrackingForAllDebuggees(cx)) {
+          dbg->enabled = false;
+          return false;
+        }
+      }
+    }
+
+    for (Breakpoint* bp = dbg->firstBreakpoint(); bp;
+         bp = bp->nextInDebugger()) {
+      if (!wasEnabled) {
+        bp->site->inc(cx->runtime()->defaultFreeOp());
+      } else {
+        bp->site->dec(cx->runtime()->defaultFreeOp());
+      }
+    }
+
+    // Add or remove ourselves from the runtime's list of Debuggers
+    // that care about new globals.
+    if (dbg->getHook(OnNewGlobalObject)) {
+      if (!wasEnabled) {
+        cx->runtime()->onNewGlobalObjectWatchers().pushBack(dbg);
+      } else {
+        cx->runtime()->onNewGlobalObjectWatchers().remove(dbg);
+      }
+    }
+
+    // Ensure the compartment is observable if we are re-enabling a
+    // Debugger with hooks that observe all execution.
+    if (!dbg->updateObservesAllExecutionOnDebuggees(
+            cx, dbg->observesAllExecution())) {
+      return false;
+    }
+
+    // Note: To toogle code coverage, we currently need to have no live
+    // stack frame, thus the coverage does not depend on the enabled flag.
+
+    dbg->updateObservesAsmJSOnDebuggees(dbg->observesAsmJS());
+  }
+
+  args.rval().setUndefined();
+  return true;
+}
+
 /* static */
 bool Debugger::getHookImpl(JSContext* cx, CallArgs& args, Debugger& dbg,
                            Hook which) {
@@ -3881,11 +3954,13 @@ bool Debugger::setOnNewGlobalObject(JSContext* cx, unsigned argc, Value* vp) {
 
   // Add or remove ourselves from the runtime's list of Debuggers that care
   // about new globals.
-  JSObject* newHook = dbg->getHook(OnNewGlobalObject);
-  if (!oldHook && newHook) {
-    cx->runtime()->onNewGlobalObjectWatchers().pushBack(dbg);
-  } else if (oldHook && !newHook) {
-    cx->runtime()->onNewGlobalObjectWatchers().remove(dbg);
+  if (dbg->enabled) {
+    JSObject* newHook = dbg->getHook(OnNewGlobalObject);
+    if (!oldHook && newHook) {
+      cx->runtime()->onNewGlobalObjectWatchers().pushBack(dbg);
+    } else if (oldHook && !newHook) {
+      cx->runtime()->onNewGlobalObjectWatchers().remove(dbg);
+    }
   }
 
   return true;
@@ -4413,13 +4488,13 @@ bool Debugger::addDebuggeeGlobal(JSContext* cx, Handle<GlobalObject*> global) {
   });
 
   // (5)
-  if (trackingAllocationSites &&
+  if (trackingAllocationSites && enabled &&
       !Debugger::addAllocationsTracking(cx, global)) {
     return false;
   }
 
   auto allocationsTrackingGuard = MakeScopeExit([&] {
-    if (trackingAllocationSites) {
+    if (trackingAllocationSites && enabled) {
       Debugger::removeAllocationsTracking(*global);
     }
   });
@@ -5846,6 +5921,7 @@ bool Debugger::adoptSource(JSContext* cx, unsigned argc, Value* vp) {
 }
 
 const JSPropertySpec Debugger::properties[] = {
+    JS_PSGS("enabled", Debugger::getEnabled, Debugger::setEnabled, 0),
     JS_PSGS("onDebuggerStatement", Debugger::getOnDebuggerStatement,
             Debugger::setOnDebuggerStatement, 0),
     JS_PSGS("onExceptionUnwind", Debugger::getOnExceptionUnwind,
@@ -6038,13 +6114,16 @@ bool Debugger::observesFrame(const FrameIter& iter) const {
 }
 
 bool Debugger::observesScript(JSScript* script) const {
+  if (!enabled) {
+    return false;
+  }
   // Don't ever observe self-hosted scripts: the Debugger API can break
   // self-hosted invariants.
   return observesGlobal(&script->global()) && !script->selfHosted();
 }
 
 bool Debugger::observesWasm(wasm::Instance* instance) const {
-  if (!instance->debugEnabled()) {
+  if (!enabled || !instance->debugEnabled()) {
     return false;
   }
   return observesGlobal(&instance->object()->global());
@@ -7157,7 +7236,7 @@ JS_PUBLIC_API bool FireOnGarbageCollectionHookRequired(JSContext* cx) {
   AutoCheckCannotGC noGC;
 
   for (Debugger* dbg : cx->runtime()->debuggerList()) {
-    if (dbg->observedGC(cx->runtime()->gc.majorGCCount()) &&
+    if (dbg->enabled && dbg->observedGC(cx->runtime()->gc.majorGCCount()) &&
         dbg->getHook(Debugger::OnGarbageCollection)) {
       return true;
     }
@@ -7177,7 +7256,7 @@ JS_PUBLIC_API bool FireOnGarbageCollectionHook(
     AutoCheckCannotGC noGC;
 
     for (Debugger* dbg : cx->runtime()->debuggerList()) {
-      if (dbg->observedGC(data->majorGCNumber()) &&
+      if (dbg->enabled && dbg->observedGC(data->majorGCNumber()) &&
           dbg->getHook(Debugger::OnGarbageCollection)) {
         if (!triggered.append(dbg->object)) {
           JS_ReportOutOfMemory(cx);
diff --git a/js/src/debugger/Debugger.h b/js/src/debugger/Debugger.h
index f25cde4da518..4f3edd0e3bb6 100644
--- a/js/src/debugger/Debugger.h
+++ b/js/src/debugger/Debugger.h
@@ -243,8 +243,8 @@ extern void CheckDebuggeeThing(JSObject* obj, bool invisibleOk);
  * not, because they are not deleted when a compartment is no longer a
  * debuggee: the values need to maintain object identity across add/remove/add
  * transitions. (Frames are an exception to the rule. Existing Debugger.Frame
- * objects are killed if their realm is removed as a debugger; if the realm
- * beacomes a debuggee again later, new Frame objects are created.)
+ * objects are killed when debugging is disabled for their compartment, and if
+ * it's re-enabled later, new Frame objects are created.)
  */
 template <class UnbarrieredKey, bool InvisibleKeysOk = false>
 class DebuggerWeakMap
@@ -445,6 +445,8 @@ class Debugger : private mozilla::LinkedListElement<Debugger> {
     return observedGCs.put(majorGCNumber);
   }
 
+  bool isEnabled() const { return enabled; }
+
   static SavedFrame* getObjectAllocationSite(JSObject& obj);
 
   struct AllocationsLogEntry {
@@ -490,6 +492,7 @@ class Debugger : private mozilla::LinkedListElement<Debugger> {
       debuggees; /* Debuggee globals. Cross-compartment weak references. */
   JS::ZoneSet debuggeeZones; /* Set of zones that we have debuggees in. */
   js::GCPtrObject uncaughtExceptionHook; /* Strong reference. */
+  bool enabled;
   bool allowUnobservedAsmJS;
 
   // Whether to enable code coverage on the Debuggee.
@@ -543,7 +546,7 @@ class Debugger : private mozilla::LinkedListElement<Debugger> {
   /*
    * Add allocations tracking for objects allocated within the given
    * debuggee's compartment. The given debuggee global must be observed by at
-   * least one Debugger that is tracking allocations.
+   * least one Debugger that is enabled and tracking allocations.
    */
   static MOZ_MUST_USE bool addAllocationsTracking(
       JSContext* cx, Handle<GlobalObject*> debuggee);
@@ -562,7 +565,7 @@ class Debugger : private mozilla::LinkedListElement<Debugger> {
   void removeAllocationsTrackingForAllDebuggees();
 
   /*
-   * If this Debugger has a onNewGlobalObject handler, then
+   * If this Debugger is enabled, and has a onNewGlobalObject handler, then
    * this link is inserted into the list headed by
    * JSRuntime::onNewGlobalObjectWatchers.
    */
@@ -599,10 +602,9 @@ class Debugger : private mozilla::LinkedListElement<Debugger> {
    * onEnterFrame handler on resume, and to retain onStep and onPop hooks.
    *
    * An entry is present in this table when:
-   *  - both the debuggee generator object and the Debugger.Frame object exists
-   *  - the debuggee generator object belongs to a relam that is a debuggee of
-   *    the Debugger.Frame's owner.
-   *
+   * -   both the debuggee generator object and the Debugger.Frame object exist
+   * -   the Debugger.Frame's owner is still an enabled debugger of
+   *     the debuggee compartment
    * regardless of whether the frame is currently suspended. (This list is
    * meant to explain why we update the table in the particular places where
    * we do so.)
@@ -773,6 +775,8 @@ class Debugger : private mozilla::LinkedListElement<Debugger> {
   static MOZ_MUST_USE bool setHookImpl(JSContext* cx, CallArgs& args,
                                        Debugger& dbg, Hook which);
 
+  static bool getEnabled(JSContext* cx, unsigned argc, Value* vp);
+  static bool setEnabled(JSContext* cx, unsigned argc, Value* vp);
   static bool getOnDebuggerStatement(JSContext* cx, unsigned argc, Value* vp);
   static bool setOnDebuggerStatement(JSContext* cx, unsigned argc, Value* vp);
   static bool getOnExceptionUnwind(JSContext* cx, unsigned argc, Value* vp);
@@ -1225,7 +1229,7 @@ class BreakpointSite {
  * site's list.
  *
  * GC rules:
- *   - script is live and breakpoint exists
+ *   - script is live, breakpoint exists, and debugger is enabled
  *      ==> debugger is live
  *   - script is live, breakpoint exists, and debugger is live
  *      ==> retain the breakpoint and the handler object is live
@@ -1344,12 +1348,16 @@ js::GCPtrNativeObject& Debugger::toJSObjectRef() {
   return object;
 }
 
-bool Debugger::observesEnterFrame() const { return getHook(OnEnterFrame); }
+bool Debugger::observesEnterFrame() const {
+  return enabled && getHook(OnEnterFrame);
+}
 
-bool Debugger::observesNewScript() const { return getHook(OnNewScript); }
+bool Debugger::observesNewScript() const {
+  return enabled && getHook(OnNewScript);
+}
 
 bool Debugger::observesNewGlobalObject() const {
-  return getHook(OnNewGlobalObject);
+  return enabled && getHook(OnNewGlobalObject);
 }
 
 bool Debugger::observesGlobal(GlobalObject* global) const {
diff --git a/js/src/debugger/DebuggerMemory.cpp b/js/src/debugger/DebuggerMemory.cpp
index 1a955feaf8ab..79f6fc1858e3 100644
--- a/js/src/debugger/DebuggerMemory.cpp
+++ b/js/src/debugger/DebuggerMemory.cpp
@@ -145,6 +145,10 @@ bool DebuggerMemory::setTrackingAllocationSites(JSContext* cx, unsigned argc,
 
   dbg->trackingAllocationSites = enabling;
 
+  if (!dbg->enabled) {
+    return undefined(args);
+  }
+
   if (enabling) {
     if (!dbg->addAllocationsTrackingForAllDebuggees(cx)) {
       dbg->trackingAllocationSites = false;
@@ -333,7 +337,7 @@ bool DebuggerMemory::setAllocationSamplingProbability(JSContext* cx,
 
     // If this is a change any debuggees would observe, have all debuggee
     // realms recompute their sampling probabilities.
-    if (dbg->trackingAllocationSites) {
+    if (dbg->enabled && dbg->trackingAllocationSites) {
       for (auto r = dbg->debuggees.all(); !r.empty(); r.popFront()) {
         r.front()->realm()->chooseAllocationSamplingProbability();
       }
diff --git a/js/src/debugger/NoExecute.cpp b/js/src/debugger/NoExecute.cpp
index 39295a1a0abf..026d6aa25cba 100644
--- a/js/src/debugger/NoExecute.cpp
+++ b/js/src/debugger/NoExecute.cpp
@@ -40,7 +40,8 @@ EnterDebuggeeNoExecute* EnterDebuggeeNoExecute::findInStack(JSContext* cx) {
   for (EnterDebuggeeNoExecute* it = cx->noExecuteDebuggerTop; it;
        it = it->prev_) {
     Debugger& dbg = it->debugger();
-    if (!it->unlocked_ && dbg.observesGlobal(debuggee->maybeGlobal())) {
+    if (!it->unlocked_ && dbg.isEnabled() &&
+        dbg.observesGlobal(debuggee->maybeGlobal())) {
       return it;
     }
   }
diff --git a/js/src/debugger/NoExecute.h b/js/src/debugger/NoExecute.h
index a88fc7b5b4f8..fbdf91a56430 100644
--- a/js/src/debugger/NoExecute.h
+++ b/js/src/debugger/NoExecute.h
@@ -19,8 +19,8 @@ namespace js {
 
 class LeaveDebuggeeNoExecute;
 
-// Prevents all the debuggeee compartments of a given Debugger from executing
-// scripts. Attempts to run script will throw an
+// Given a Debugger instance dbg, if it is enabled, prevents all its debuggee
+// compartments from executing scripts. Attempts to run script will throw an
 // instance of Debugger.DebuggeeWouldRun from the topmost locked Debugger's
 // compartment.
 class MOZ_RAII EnterDebuggeeNoExecute {
diff --git a/js/src/jit-test/tests/binast/lazy/debug/Debugger-allowUnobservedAsmJS-01.binjs b/js/src/jit-test/tests/binast/lazy/debug/Debugger-allowUnobservedAsmJS-01.binjs
index 253946f4f018..dfa600300073 100644
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diff --git a/js/src/jit-test/tests/binast/lazy/debug/Debugger-enabled-01.binjs b/js/src/jit-test/tests/binast/lazy/debug/Debugger-enabled-01.binjs
new file mode 100644
index 000000000000..374ac5ee20f2
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diff --git a/js/src/jit-test/tests/binast/lazy/debug/Debugger-onNewGlobalObject-04.binjs b/js/src/jit-test/tests/binast/lazy/debug/Debugger-onNewGlobalObject-04.binjs
index d09b375ecb8e..42d988d31017 100644
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diff --git a/js/src/jit-test/tests/binast/lazy/debug/Frame-onPop-disabled.binjs b/js/src/jit-test/tests/binast/lazy/debug/Frame-onPop-disabled.binjs
new file mode 100644
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diff --git a/js/src/jit-test/tests/binast/lazy/debug/Frame-onPop-multiple-03.binjs b/js/src/jit-test/tests/binast/lazy/debug/Frame-onPop-multiple-03.binjs
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diff --git a/js/src/jit-test/tests/binast/lazy/debug/dispatch-02.binjs b/js/src/jit-test/tests/binast/lazy/debug/dispatch-02.binjs
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diff --git a/js/src/jit-test/tests/binast/nonlazy/debug/Debugger-allowUnobservedAsmJS-01.binjs b/js/src/jit-test/tests/binast/nonlazy/debug/Debugger-allowUnobservedAsmJS-01.binjs
index 253946f4f018..dfa600300073 100644
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diff --git a/js/src/jit-test/tests/binast/nonlazy/debug/Debugger-enabled-01.binjs b/js/src/jit-test/tests/binast/nonlazy/debug/Debugger-enabled-01.binjs
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index b36332f3580d..ff2e0458b48d 100644
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diff --git a/js/src/jit-test/tests/binast/nonlazy/debug/Debugger-onNewGlobalObject-07.binjs b/js/src/jit-test/tests/binast/nonlazy/debug/Debugger-onNewGlobalObject-07.binjs
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diff --git a/js/src/jit-test/tests/binast/nonlazy/debug/Frame-onPop-disabled.binjs b/js/src/jit-test/tests/binast/nonlazy/debug/Frame-onPop-disabled.binjs
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diff --git a/js/src/jit-test/tests/binast/nonlazy/debug/Frame-onPop-multiple-03.binjs b/js/src/jit-test/tests/binast/nonlazy/debug/Frame-onPop-multiple-03.binjs
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index 000000000000..55e8af81639b
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diff --git a/js/src/jit-test/tests/binast/nonlazy/debug/dispatch-02.binjs b/js/src/jit-test/tests/binast/nonlazy/debug/dispatch-02.binjs
new file mode 100644
index 000000000000..57729afb0b32
Binary files /dev/null and b/js/src/jit-test/tests/binast/nonlazy/debug/dispatch-02.binjs differ
diff --git a/js/src/jit-test/tests/debug/Debugger-allowUnobservedAsmJS-01.js b/js/src/jit-test/tests/debug/Debugger-allowUnobservedAsmJS-01.js
index 51f9d033d50c..afa2589ef48d 100644
--- a/js/src/jit-test/tests/debug/Debugger-allowUnobservedAsmJS-01.js
+++ b/js/src/jit-test/tests/debug/Debugger-allowUnobservedAsmJS-01.js
@@ -21,6 +21,14 @@ assertEq(asmLink(asmCompile(asmFunStr))(), undefined);
 g.dbg.allowUnobservedAsmJS = false;
 assertAsmTypeFail(asmFunStr);
 
+// Disabling the debugger should uninhibit.
+g.dbg.enabled = false;
+assertEq(asmLink(asmCompile(asmFunStr))(), undefined);
+
+// Enabling it should inhibit again.
+g.dbg.enabled = true;
+assertAsmTypeFail(asmFunStr);
+
 // Removing the global should lift the inhibition.
 g.dbg.removeDebuggee(this);
 assertEq(asmLink(asmCompile(asmFunStr))(), undefined);
diff --git a/js/src/jit-test/tests/debug/Debugger-enabled-01.js b/js/src/jit-test/tests/debug/Debugger-enabled-01.js
new file mode 100644
index 000000000000..e542c02a51fd
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Debugger-enabled-01.js
@@ -0,0 +1,18 @@
+var desc = Object.getOwnPropertyDescriptor(Debugger.prototype, "enabled");
+assertEq(typeof desc.get, 'function');
+assertEq(typeof desc.set, 'function');
+
+var g = newGlobal({newCompartment: true});
+var hits;
+var dbg = new Debugger(g);
+assertEq(dbg.enabled, true);
+dbg.onDebuggerStatement = function () { hits++; };
+
+var vals = [true, false, null, undefined, NaN, "blah", {}];
+for (var i = 0; i < vals.length; i++) {
+    dbg.enabled = vals[i];
+    assertEq(dbg.enabled, !!vals[i]);
+    hits = 0;
+    g.eval("debugger;");
+    assertEq(hits, vals[i] ? 1 : 0);
+}
diff --git a/js/src/jit-test/tests/debug/Debugger-enabled-02.js b/js/src/jit-test/tests/debug/Debugger-enabled-02.js
new file mode 100644
index 000000000000..35f073781736
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Debugger-enabled-02.js
@@ -0,0 +1,17 @@
+// Tests that hooks work if set while the Debugger is disabled.
+
+var g = newGlobal({newCompartment: true});
+var dbg = new Debugger(g);
+var log = "";
+
+g.eval("" + function f() { return 42; });
+
+dbg.enabled = false;
+dbg.onEnterFrame = function (frame) {
+  log += "1";
+};
+dbg.enabled = true;
+
+g.f();
+
+assertEq(log, "1");
diff --git a/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-04.js b/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-04.js
index 6e02d19bdce7..096a2deadfe0 100644
--- a/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-04.js
+++ b/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-04.js
@@ -12,3 +12,13 @@ dbg.onNewGlobalObject = function (global) {
 log = '';
 newGlobal();
 assertEq(log, 'n');
+
+log = '';
+dbg.enabled = false;
+newGlobal();
+assertEq(log, '');
+
+log = '';
+dbg.enabled = true;
+newGlobal();
+assertEq(log, 'n');
diff --git a/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-07.js b/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-07.js
index eb79ea4fcce9..15c8568e0209 100644
--- a/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-07.js
+++ b/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-07.js
@@ -9,10 +9,12 @@ var hit;
 function handler(global) {
   hit++;
   log += hit;
+  if (hit == 2)
+    dbg1.enabled = dbg2.enabled = dbg3.enabled = false;
 };
 
 log = '';
 hit = 0;
 dbg1.onNewGlobalObject = dbg2.onNewGlobalObject = dbg3.onNewGlobalObject = handler;
 newGlobal();
-assertEq(log, '123');
+assertEq(log, '12');
diff --git a/js/src/jit-test/tests/debug/Debugger-onNewPromise-01.js b/js/src/jit-test/tests/debug/Debugger-onNewPromise-01.js
index 9788e027c9e7..cf3626ece035 100644
--- a/js/src/jit-test/tests/debug/Debugger-onNewPromise-01.js
+++ b/js/src/jit-test/tests/debug/Debugger-onNewPromise-01.js
@@ -10,4 +10,8 @@ let promisesFound = [];
 dbg.onNewPromise = p => { promisesFound.push(p); };
 
 let p1 = new g.Promise(function (){});
+dbg.enabled = false;
+let p2 = new g.Promise(function (){});
+
 assertEq(promisesFound.indexOf(gw.makeDebuggeeValue(p1)) != -1, true);
+assertEq(promisesFound.indexOf(gw.makeDebuggeeValue(p2)) == -1, true);
diff --git a/js/src/jit-test/tests/debug/Debugger-onPromiseSettled-01.js b/js/src/jit-test/tests/debug/Debugger-onPromiseSettled-01.js
index 84f832399796..afb22f4bc405 100644
--- a/js/src/jit-test/tests/debug/Debugger-onPromiseSettled-01.js
+++ b/js/src/jit-test/tests/debug/Debugger-onPromiseSettled-01.js
@@ -16,3 +16,10 @@ g.settlePromiseNow(p);
 
 assertEq(log, "s");
 assertEq(pw, gw.makeDebuggeeValue(p));
+
+log = "";
+dbg.enabled = false;
+p = new g.Promise(function (){});
+g.settlePromiseNow(p);
+
+assertEq(log, "");
diff --git a/js/src/jit-test/tests/debug/Frame-onPop-disabled.js b/js/src/jit-test/tests/debug/Frame-onPop-disabled.js
new file mode 100644
index 000000000000..59d6d5903f3d
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-onPop-disabled.js
@@ -0,0 +1,44 @@
+// An onPop handler in a disabled Debugger's frame shouldn't fire.
+
+var g = newGlobal({newCompartment: true});
+var dbg = new Debugger(g);
+g.eval('function f() { debugger; }');
+var log;
+dbg.onEnterFrame = function handleEnterFrame(f) {
+    log += '(';
+    assertEq(f.callee.name, 'f');
+    f.onPop = function handlePop(c) {
+        log += ')';
+        assertEq(dbg.enabled, true);
+    };
+};
+
+var enable;
+dbg.onDebuggerStatement = function handleDebugger(f) {
+    dbg.enabled = enable;
+}
+
+
+// This should fire the onEnterFrame and onPop handlers.
+log = 'a';
+enable = true;
+g.f();
+
+// This should fire the onEnterFrame handler, but not the onPop.
+log += 'b';
+enable = false;
+g.f();
+
+// This should fire neither.
+log += 'c';
+dbg.enabled = false;
+enable = false;
+g.f();
+
+// This should fire both again.
+log += 'd';
+dbg.enabled = true;
+enable = true;
+g.f();
+
+assertEq(log, 'a()b(cd()');
diff --git a/js/src/jit-test/tests/debug/Frame-onPop-multiple-03.js b/js/src/jit-test/tests/debug/Frame-onPop-multiple-03.js
new file mode 100644
index 000000000000..1bc2dea0bb0b
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-onPop-multiple-03.js
@@ -0,0 +1,36 @@
+// One Debugger's onPop handler can disable another Debugger.
+var g = newGlobal({newCompartment: true});
+var dbg1 = new Debugger(g);
+var dbg2 = new Debugger(g);
+
+var log;
+var frames = [];
+var firstPop = true;
+
+function handleEnter(frame) {
+    log += '(';
+    frames.push(frame);
+    frame.debugger = this;
+    frame.onPop = function handlePop(completion) {
+        log += ')';
+        assertEq(completion.return, 42);
+        if (firstPop) {
+            // We can't say which frame's onPop handler will get called first.
+            if (this == frames[0])
+                frames[1].debugger.enabled = false;
+            else
+                frames[0].debugger.enabled = false;
+        } else {
+            assertEq("second pop handler was called",
+                     "second pop handler should not be called");
+        }
+        firstPop = false;
+    };
+};
+
+dbg1.onEnterFrame = handleEnter;
+dbg2.onEnterFrame = handleEnter;
+
+log = '';
+assertEq(g.eval('40 + 2'), 42);
+assertEq(log, '(()');
diff --git a/js/src/jit-test/tests/debug/Memory-drainAllocationsLog-12.js b/js/src/jit-test/tests/debug/Memory-drainAllocationsLog-12.js
new file mode 100644
index 000000000000..4049f5f96a18
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Memory-drainAllocationsLog-12.js
@@ -0,0 +1,17 @@
+// Test that disabling the debugger disables allocation tracking.
+
+load(libdir + "asserts.js");
+
+const dbg = new Debugger();
+const root = newGlobal({newCompartment: true});
+dbg.addDebuggee(root);
+
+dbg.memory.trackingAllocationSites = true;
+dbg.enabled = false;
+
+root.eval("this.alloc = {}");
+
+// We shouldn't accumulate allocations in our log while the debugger is
+// disabled.
+let allocs = dbg.memory.drainAllocationsLog();
+assertEq(allocs.length, 0);
diff --git a/js/src/jit-test/tests/debug/Memory-trackingAllocationSites-03.js b/js/src/jit-test/tests/debug/Memory-trackingAllocationSites-03.js
index 62205b82499e..d29fe6404510 100644
--- a/js/src/jit-test/tests/debug/Memory-trackingAllocationSites-03.js
+++ b/js/src/jit-test/tests/debug/Memory-trackingAllocationSites-03.js
@@ -74,3 +74,32 @@ test("Setting trackingAllocationSites to true should throw if the debugger " +
        assertEq(isTrackingAllocations(root1, d1r1), false);
        assertEq(isTrackingAllocations(root2, d1r2), false);
      });
+
+test("A Debugger isn't tracking allocation sites when disabled.",
+     () => {
+       dbg1.memory.trackingAllocationSites = true;
+       let d1r1 = dbg1.addDebuggee(root1);
+
+       assertEq(isTrackingAllocations(root1, d1r1), true);
+       dbg1.enabled = false;
+       assertEq(isTrackingAllocations(root1, d1r1), false);
+     });
+
+test("Re-enabling throws an error if we can't reinstall allocations tracking " +
+     "for all debuggees.",
+     () => {
+       dbg1.enabled = false
+       dbg1.memory.trackingAllocationSites = true;
+       let d1r1 = dbg1.addDebuggee(root1);
+       let d1r2 = dbg1.addDebuggee(root2);
+
+       // Can't install allocation hooks for root2 with this set.
+       root2.enableShellAllocationMetadataBuilder();
+
+       assertThrowsInstanceOf(() => dbg1.enabled = true,
+                              Error);
+
+       assertEq(dbg1.enabled, false);
+       assertEq(isTrackingAllocations(root1, d1r1), false);
+       assertEq(isTrackingAllocations(root2, d1r2), false);
+     });
diff --git a/js/src/jit-test/tests/debug/dispatch-02.js b/js/src/jit-test/tests/debug/dispatch-02.js
new file mode 100644
index 000000000000..05ebfd6c7edd
--- /dev/null
+++ b/js/src/jit-test/tests/debug/dispatch-02.js
@@ -0,0 +1,21 @@
+// Disabling a Debugger object causes events to stop being delivered to it
+// immediately, even if we're in the middle of dispatching.
+
+var g = newGlobal({newCompartment: true});
+var log;
+
+var arr = [];
+for (var i = 0; i < 4; i++) {
+    arr[i] = new Debugger(g);
+    arr[i].num = i;
+    arr[i].onDebuggerStatement = function () {
+        log += this.num;
+        // Disable them all.
+        for (var j = 0; j < arr.length; j++)
+            arr[j].enabled = false;
+    };
+}
+
+log = '';
+g.eval("debugger; debugger;");
+assertEq(log, '0');
diff --git a/js/src/jit-test/tests/debug/noExecute-04.js b/js/src/jit-test/tests/debug/noExecute-04.js
index 628a425bad76..69770d9b22a1 100644
--- a/js/src/jit-test/tests/debug/noExecute-04.js
+++ b/js/src/jit-test/tests/debug/noExecute-04.js
@@ -22,6 +22,10 @@ var handlers = [() => { g.f(); },
 function testHookEnabled(hookName, trigger) {
   for (var h of handlers) {
     assertThrowsInstanceOf(h, Debugger.DebuggeeWouldRun);
+    dbg.enabled = false;
+    h();
+    dbg.enabled = true;
+    assertThrowsInstanceOf(h, Debugger.DebuggeeWouldRun);
   }
 }
 
diff --git a/js/src/jit-test/tests/debug/onEnterFrame-generator-04.js b/js/src/jit-test/tests/debug/onEnterFrame-generator-04.js
index 00f9d0f3b4fa..6fcc1c6a9895 100644
--- a/js/src/jit-test/tests/debug/onEnterFrame-generator-04.js
+++ b/js/src/jit-test/tests/debug/onEnterFrame-generator-04.js
@@ -34,7 +34,7 @@ function test(mode, expected) {
             log += x;
     `);
     assertEq(g.log, expected);
-    dbg.removeDebuggee(g);
+    dbg.enabled = false;
 }
 
 // We fire onEnterFrame for the initial activation when a generator is first
diff --git a/js/xpconnect/tests/unit/test_onGarbageCollection-04.js b/js/xpconnect/tests/unit/test_onGarbageCollection-04.js
index 72e6d3228497..6cb532d9773c 100644
--- a/js/xpconnect/tests/unit/test_onGarbageCollection-04.js
+++ b/js/xpconnect/tests/unit/test_onGarbageCollection-04.js
@@ -65,7 +65,7 @@ function run_test() {
       ok(debuggeree.fired >= 1);
       ok(fired >= 1);
 
-      debuggeree.dbg.removeAllDebuggees();
+      debuggeree.dbg.enabled = dbg.enabled = false;
       do_test_finished();
     });
   });