Backed out changeset 8739b71b8bd9 (bug 1740499) as requested by smaug

layout/base/PresShell.cpp

@@ -3924,46 +3924,21 @@ void PresShell::UnsuppressAndInvalidate() {
   PROFILER_MARKER_UNTYPED("UnsuppressAndInvalidate", GRAPHICS);
 
   mPaintingSuppressed = false;
-
-  if (mPresContext->IsRootContentDocumentCrossProcess()) {
-    nsWeakPtr weakDoc = do_GetWeakReference(mDocument);
-    // Tell the parent process about the unsuppression, but make sure to have
-    // done a refresh driver tick first at least. That should improve the
-    // chances that we have something meaningful to display.
-    mPresContext->RegisterManagedPostRefreshObserver(
-        new ManagedPostRefreshObserver(
-            mPresContext, [weakDoc](bool aWasCanceled) {
-              if (aWasCanceled) {
-                return ManagedPostRefreshObserver::Unregister::Yes;
-              }
-
-              nsCOMPtr<Document> doc = do_QueryReferent(weakDoc);
-              if (!doc) {
-                return ManagedPostRefreshObserver::Unregister::Yes;
-              }
-              nsPresContext* pctx = doc->GetPresContext();
-              if (!pctx) {
-                return ManagedPostRefreshObserver::Unregister::Yes;
-              }
-
-              if (auto* bc = BrowserChild::GetFrom(doc->GetDocShell())) {
-                if (doc->IsInitialDocument()) {
-                  bc->SendDidUnsuppressPaintingNormalPriority();
-                } else {
-                  bc->SendDidUnsuppressPainting();
-                }
-              }
-
-              return ManagedPostRefreshObserver::Unregister::Yes;
-            }));
-    mPresContext->SetWantsExtraTick();
-  }
-
   if (nsIFrame* rootFrame = mFrameConstructor->GetRootFrame()) {
     // let's assume that outline on a root frame is not supported
     rootFrame->InvalidateFrame();
   }
 
+  if (mPresContext->IsRootContentDocumentCrossProcess()) {
+    if (auto* bc = BrowserChild::GetFrom(mDocument->GetDocShell())) {
+      if (mDocument->IsInitialDocument()) {
+        bc->SendDidUnsuppressPaintingNormalPriority();
+      } else {
+        bc->SendDidUnsuppressPainting();
+      }
+    }
+  }
+
   // now that painting is unsuppressed, focus may be set on the document
   if (nsPIDOMWindowOuter* win = mDocument->GetWindow()) {
     win->SetReadyForFocus();

layout/base/nsPresContext.cpp

@@ -282,7 +282,6 @@ nsPresContext::nsPresContext(dom::Document* aDocument, nsPresContextType aType)
       mHadContentfulPaint(false),
       mHadNonTickContentfulPaint(false),
       mHadContentfulPaintComposite(false),
-      mWantsExtraTick(false),
 #ifdef DEBUG
       mInitialized(false),
 #endif
@@ -410,7 +409,6 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsPresContext)
   tmp->Destroy();
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
-
 bool nsPresContext::IsChrome() const {
   return Document()->IsInChromeDocShell();
 }

layout/base/nsPresContext.h

@@ -1086,14 +1086,6 @@ class nsPresContext : public nsISupports, public mozilla::SupportsWeakPtr {
     return mFontFeatureValuesLookup;
   }
 
-  void SetWantsExtraTick() { mWantsExtraTick = true; }
-
-  bool TakeWantsExtraTick() {
-    bool retVal = mWantsExtraTick;
-    mWantsExtraTick = false;
-    return retVal;
-  }
-
  protected:
   friend class nsRunnableMethod<nsPresContext>;
   void ThemeChangedInternal();
@@ -1378,8 +1370,6 @@ class nsPresContext : public nsISupports, public mozilla::SupportsWeakPtr {
   // Has NotifyDidPaintForSubtree been called for a contentful paint?
   unsigned mHadContentfulPaintComposite : 1;
 
-  unsigned mWantsExtraTick : 1;
-
 #ifdef DEBUG
   unsigned mInitialized : 1;
 #endif

layout/base/nsRefreshDriver.cpp

@@ -1529,19 +1529,12 @@ void nsRefreshDriver::EnsureTimerStarted(EnsureTimerStartedFlags aFlags) {
     mRefreshTimerStartedCause = profiler_capture_backtrace();
   }
 
-  if (IsFrozen() || !mPresContext) {
-    // If we don't want to start it now, or we've been disconnected.
-    StopTimer();
-    return;
-  }
-
   // will it already fire, and no other changes needed?
   if (mActiveTimer && !(aFlags & eForceAdjustTimer)) {
-    // If we're being called from within a user input handler or someone
+    // If we're being called from within a user input handler, and we think
-    // explicitly asked for an extra tick, and we think there's time to rush an
+    // there's time to rush an extra tick immediately, then schedule a runnable
-    // extra tick immediately, then schedule a runnable to run the extra tick.
+    // to run the extra tick.
-    if ((mPresContext->TakeWantsExtraTick() || mUserInputProcessingCount) &&
+    if (mUserInputProcessingCount && CanDoExtraTick()) {
-        CanDoExtraTick()) {
       RefPtr<nsRefreshDriver> self = this;
       NS_DispatchToCurrentThreadQueue(
           NS_NewRunnableFunction(
@@ -1563,6 +1556,12 @@ void nsRefreshDriver::EnsureTimerStarted(EnsureTimerStartedFlags aFlags) {
     return;
   }
 
+  if (IsFrozen() || !mPresContext) {
+    // If we don't want to start it now, or we've been disconnected.
+    StopTimer();
+    return;
+  }
+
   if (mPresContext->Document()->IsBeingUsedAsImage()) {
     // Image documents receive ticks from clients' refresh drivers.
     // XXXdholbert Exclude SVG-in-opentype fonts from this optimization, until