Backed out changeset 55f827545de2 (bug 1701303) for causing bustages on ContentParent.cpp. CLOSED TREE

docshell/base/nsDocShell.cpp

@@ -273,6 +273,9 @@ static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
 // Number of documents currently loading
 static int32_t gNumberOfDocumentsLoading = 0;
 
+// Global count of docshells with the private attribute set
+static uint32_t gNumberOfPrivateDocShells = 0;
+
 static mozilla::LazyLogModule gCharsetMenuLog("CharsetMenu");
 
 #define LOGCHARSETMENU(args) \
@@ -304,6 +307,33 @@ static void FavorPerformanceHint(bool aPerfOverStarvation) {
   }
 }
 
+static void IncreasePrivateDocShellCount() {
+  gNumberOfPrivateDocShells++;
+  if (gNumberOfPrivateDocShells > 1 || !XRE_IsContentProcess()) {
+    return;
+  }
+
+  mozilla::dom::ContentChild* cc = mozilla::dom::ContentChild::GetSingleton();
+  cc->SendPrivateDocShellsExist(true);
+}
+
+static void DecreasePrivateDocShellCount() {
+  MOZ_ASSERT(gNumberOfPrivateDocShells > 0);
+  gNumberOfPrivateDocShells--;
+  if (!gNumberOfPrivateDocShells) {
+    if (XRE_IsContentProcess()) {
+      dom::ContentChild* cc = dom::ContentChild::GetSingleton();
+      cc->SendPrivateDocShellsExist(false);
+      return;
+    }
+
+    nsCOMPtr<nsIObserverService> obsvc = services::GetObserverService();
+    if (obsvc) {
+      obsvc->NotifyObservers(nullptr, "last-pb-context-exited", nullptr);
+    }
+  }
+}
+
 static bool IsTopLevelDoc(BrowsingContext* aBrowsingContext,
                           nsILoadInfo* aLoadInfo) {
   MOZ_ASSERT(aBrowsingContext);
@@ -381,6 +411,7 @@ nsDocShell::nsDocShell(BrowsingContext* aBrowsingContext,
       mIsBeingDestroyed(false),
       mIsExecutingOnLoadHandler(false),
       mSavingOldViewer(false),
+      mAffectPrivateSessionLifetime(true),
       mInvisible(false),
       mHasLoadedNonBlankURI(false),
       mBlankTiming(false),
@@ -1686,6 +1717,14 @@ nsDocShell::GetUsePrivateBrowsing(bool* aUsePrivateBrowsing) {
 void nsDocShell::NotifyPrivateBrowsingChanged() {
   MOZ_ASSERT(!mIsBeingDestroyed);
 
+  if (mAffectPrivateSessionLifetime) {
+    if (UsePrivateBrowsing()) {
+      IncreasePrivateDocShellCount();
+    } else {
+      DecreasePrivateDocShellCount();
+    }
+  }
+
   nsTObserverArray<nsWeakPtr>::ForwardIterator iter(mPrivacyObservers);
   while (iter.HasMore()) {
     nsWeakPtr ref = iter.GetNext();
@@ -1738,6 +1777,35 @@ nsDocShell::SetRemoteSubframes(bool aUseRemoteSubframes) {
   return mBrowsingContext->SetRemoteSubframes(aUseRemoteSubframes);
 }
 
+NS_IMETHODIMP
+nsDocShell::SetAffectPrivateSessionLifetime(bool aAffectLifetime) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  bool change = aAffectLifetime != mAffectPrivateSessionLifetime;
+  if (change && UsePrivateBrowsing()) {
+    if (aAffectLifetime) {
+      IncreasePrivateDocShellCount();
+    } else {
+      DecreasePrivateDocShellCount();
+    }
+  }
+  mAffectPrivateSessionLifetime = aAffectLifetime;
+
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> shell = do_QueryObject(child);
+    if (shell) {
+      shell->SetAffectPrivateSessionLifetime(aAffectLifetime);
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAffectPrivateSessionLifetime(bool* aAffectLifetime) {
+  *aAffectLifetime = mAffectPrivateSessionLifetime;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDocShell::AddWeakPrivacyTransitionObserver(
     nsIPrivacyTransitionObserver* aObserver) {
@@ -2533,6 +2601,8 @@ nsresult nsDocShell::SetDocLoaderParent(nsDocLoader* aParent) {
       value = false;
     }
     SetAllowDNSPrefetch(mAllowDNSPrefetch && value);
+    SetAffectPrivateSessionLifetime(
+        parentAsDocShell->GetAffectPrivateSessionLifetime());
 
     // We don't need to inherit metaViewportOverride, because the viewport
     // is only relevant for the outermost nsDocShell, not for any iframes
@@ -4457,6 +4527,10 @@ nsDocShell::Destroy() {
   // to break the cycle between us and the timers.
   CancelRefreshURITimers();
 
+  if (UsePrivateBrowsing() && mAffectPrivateSessionLifetime) {
+    DecreasePrivateDocShellCount();
+  }
+
   return NS_OK;
 }