Bug 1324359 - Rename and simplify the DocShell ProcessLock concept, r=smaug

MozReview-Commit-ID: JTp8Q2mWqpN

docshell/base/nsDocShell.cpp

@@ -14739,44 +14739,31 @@ nsDocShell::GetCommandManager()
 }
 
 NS_IMETHODIMP
-nsDocShell::GetIsProcessLocked(bool* aIsLocked)
+nsDocShell::GetIsOnlyToplevelInTabGroup(bool* aResult)
 {
-  MOZ_ASSERT(aIsLocked);
-  *aIsLocked = GetProcessLockReason() != PROCESS_LOCK_NONE;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsDocShell::GetProcessLockReason(uint32_t* aReason)
-{
-  MOZ_ASSERT(aReason);
+  MOZ_ASSERT(aResult);
 
   nsPIDOMWindowOuter* outer = GetWindow();
   MOZ_ASSERT(outer);
 
-  // Check if we are a toplevel window
+  // If we are not toplevel then we are not the only toplevel window in the tab
+  // group.
   if (outer->GetScriptableParentOrNull()) {
-    *aReason = PROCESS_LOCK_IFRAME;
+    *aResult = false;
     return NS_OK;
   }
 
-  // If we have any other toplevel windows in our tab group, then we cannot
-  // perform the navigation.
+  // If we have any other toplevel windows in our tab group, then we are not the
+  // only toplevel window in the tab group.
   nsTArray<nsPIDOMWindowOuter*> toplevelWindows =
     outer->TabGroup()->GetTopLevelWindows();
   if (toplevelWindows.Length() > 1) {
-    *aReason = PROCESS_LOCK_RELATED_CONTEXTS;
+    *aResult = false;
     return NS_OK;
   }
   MOZ_ASSERT(toplevelWindows.Length() == 1);
   MOZ_ASSERT(toplevelWindows[0] == outer);
 
-  // If we aren't in a content process, we cannot perform a cross-process load.
-  if (!XRE_IsContentProcess()) {
-    *aReason = PROCESS_LOCK_NON_CONTENT;
-    return NS_OK;
-  }
-
-  *aReason = PROCESS_LOCK_NONE;
+  *aResult = true;
   return NS_OK;
 }

docshell/base/nsIDocShell.idl

@@ -1112,38 +1112,16 @@ interface nsIDocShell : nsIDocShellTreeItem
   const unsigned long TOUCHEVENTS_OVERRIDE_NONE = 2;
 
   /**
-   * A DocShell is locked to the current process if it would be
-   * content-observable for a process switch to occur before performing a
-   * navigation load. It is important to ensure that a DocShell is not process
-   * locked before performing process changing loads.
-   */
-  [infallible] readonly attribute boolean isProcessLocked;
-  /**
-   * Return PROCESS_LOCK_NONE if docShell is not locked to current process,
-   * otherwise return the reason why process is locked.
-   */
-  [infallible] readonly attribute unsigned long processLockReason;
-  /**
-   * The DocShell is not locked to the current process, and a navigation may
-   * proceed in a new process.
-   */
-  const unsigned long PROCESS_LOCK_NONE = 0;
-  /**
-   * The DocShell is locked to the current process because it is not a
-   * toplevel browsing context.
-   */
-  const unsigned long PROCESS_LOCK_IFRAME = 1;
-  /**
-   * The DocShell is locked to the current process because there exist other
-   * related browsing contexts which may be holding a reference.
-   */
-  const unsigned long PROCESS_LOCK_RELATED_CONTEXTS = 2;
-  /**
-   * The DocShell is locked to the current process because the current
-   * process is not a content process.
+   * This value is `true` if its corresponding unit of related browsing contexts
+   * (TabGroup) contains only 1 toplevel window, and that window is the outer
+   * window corresponding to this docshell.
    *
-   * NOTE: Some loads may not consider this a hard process lock, and may wish to
-   * ignore this reason.
+   * The value is `false` otherwise. This is the case if the docshell is an
+   * iframe, has window.opener set, or another window with window.opener
+   * referring to this window exists.
+   *
+   * If this value is `false`, it would be web content visible for a load
+   * occuring in this docshell to be performed within a different docshell.
    */
-  const unsigned long PROCESS_LOCK_NON_CONTENT = 3;
+  [infallible] readonly attribute boolean isOnlyToplevelInTabGroup;
 };

dom/base/nsContentUtils.cpp

@@ -9702,39 +9702,28 @@ nsContentUtils::AttemptLargeAllocationLoad(nsIHttpChannel* aChannel)
     return false;
   }
 
-  nsIDocShell* docShell = outer->GetDocShell();
   nsIDocument* doc = outer->GetExtantDoc();
 
-  // If the docshell is not allowed to change process, report an error based on
-  // the reason
-  const char* errorName = nullptr;
-  switch (docShell->GetProcessLockReason()) {
-    case nsIDocShell::PROCESS_LOCK_NON_CONTENT:
-      errorName = "LargeAllocationNonE10S";
-      break;
-    case nsIDocShell::PROCESS_LOCK_IFRAME:
-      errorName = "LargeAllocationIFrame";
-      break;
-    case nsIDocShell::PROCESS_LOCK_RELATED_CONTEXTS:
-      errorName = "LargeAllocationRelatedBrowsingContexts";
-      break;
-    case nsIDocShell::PROCESS_LOCK_NONE:
-      // Don't print a warning, we're allowed to change processes!
-      break;
-    default:
-      MOZ_ASSERT(false, "Should be unreachable!");
-      return false;
-  }
-
-  if (errorName) {
+  if (!XRE_IsContentProcess()) {
     if (doc) {
       nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                       NS_LITERAL_CSTRING("DOM"),
                                       doc,
                                       nsContentUtils::eDOM_PROPERTIES,
-                                      errorName);
+                                      "LargeAllocationNonE10S");
     }
+    return false;
+  }
 
+  nsIDocShell* docShell = outer->GetDocShell();
+  if (!docShell->GetIsOnlyToplevelInTabGroup()) {
+    if (doc) {
+      nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
+                                      NS_LITERAL_CSTRING("DOM"),
+                                      doc,
+                                      nsContentUtils::eDOM_PROPERTIES,
+                                      "LargeAllocationRelatedBrowsingContexts");
+    }
     return false;
   }
 

dom/base/nsDocument.cpp

@@ -2964,11 +2964,16 @@ nsIDocument::PrerenderHref(nsIURI* aHref)
     return false;
   }
 
-  // Adopting an out-of-process prerendered document is conceptually similar to
-  // switching dochshell's process, since it's the same browsing context from
-  // other browsing contexts' perspective. If we're locked in current process,
-  // we can not prerender out-of-process.
-  if (docShell->GetIsProcessLocked()) {
+  // We currently do not support prerendering in documents loaded within the
+  // chrome process.
+  if (!XRE_IsContentProcess()) {
+    return false;
+  }
+
+  // Adopting an prerendered document is similar to performing a load within a
+  // different docshell, as the prerendering must have occurred in a different
+  // docshell.
+  if (!docShell->GetIsOnlyToplevelInTabGroup()) {
     return false;
   }
 

dom/locales/en-US/chrome/dom/dom.properties

@@ -314,9 +314,7 @@ GenericFileName=file
 LargeAllocationSuccess=This page was loaded in a new process due to a Large-Allocation header.
 # LOCALIZATION NOTE: Do not translate "Large-Allocation", as it is a literal header name. Do not translate GET.
 LargeAllocationNonGetRequest=A Large-Allocation header was ignored due to the load being triggered by a non-GET request.
-# LOCALIZATION NOTE: Do not translate "Large-Allocation", as it is a literal header name
-LargeAllocationRelatedBrowsingContexts=A Large-Allocation header was ignored due to the presence of windows which have a reference to this browsing context.
-# LOCALIZATION NOTE: Do not translate "Large-Allocation", as it is a literal header name
-LargeAllocationInIFrame=A Large-Allocation header was ignored due to the load occuring within an iframe.
+# LOCALIZATION NOTE: Do not translate "Large-Allocation", as it is a literal header name. Do not translate `window.opener`.
+LargeAllocationRelatedBrowsingContexts=A Large-Allocation header was ignored due to the presence of windows which have a reference to this browsing context through the frame hierarchy or window.opener.
 # LOCALIZATION NOTE: Do not translate "Large-Allocation", as it is a literal header name
 LargeAllocationNonE10S=A Large-Allocation header was ignored due to the document not being loaded out of process.