Bug 827188 - Initialize the hidden private window lazily; r=bzbarsky

content/base/src/nsCCUncollectableMarker.cpp

@@ -368,6 +368,9 @@ nsCCUncollectableMarker::Observe(nsISupports* aSubject, const char* aTopic,
       MarkDocShell(shellTreeNode, cleanupJS, prepareForCC);
     }
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+    bool hasHiddenPrivateWindow = false;
+    appShell->GetHasHiddenPrivateWindow(&hasHiddenPrivateWindow);
+    if (hasHiddenPrivateWindow) {
       appShell->GetHiddenPrivateWindow(getter_AddRefs(hw));
       if (hw) {
         nsCOMPtr<nsIDocShell> shell;
@@ -375,6 +378,7 @@ nsCCUncollectableMarker::Observe(nsISupports* aSubject, const char* aTopic,
         nsCOMPtr<nsIDocShellTreeNode> shellTreeNode = do_QueryInterface(shell);
         MarkDocShell(shellTreeNode, cleanupJS, prepareForCC);
       }
+    }
 #endif
   }
 

docshell/base/nsDocShell.cpp

@@ -193,7 +193,10 @@
 #include "mozilla/Telemetry.h"
 #include "nsISecurityUITelemetry.h"
 
-#ifndef MOZ_PER_WINDOW_PRIVATE_BROWSING
+#ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+#include "nsIAppShellService.h"
+#include "nsAppShellCID.h"
+#else
 #include "nsIPrivateBrowsingService.h"
 #endif
 
@@ -220,9 +223,9 @@ static uint32_t gNumberOfPrivateDocShells = 0;
 
 // Global count of private docshells which will always remain open
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
-static const uint32_t kNumberOfAlwaysOpenPrivateDocShells = 1; // the private hidden window
+static uint32_t gNumberOfAlwaysOpenPrivateDocShells = 0; // the private hidden window
 #else
-static const uint32_t kNumberOfAlwaysOpenPrivateDocShells = 0;
+static const uint32_t gNumberOfAlwaysOpenPrivateDocShells = 0;
 #endif
 
 // Global reference to the URI fixup service.
@@ -688,11 +691,27 @@ ConvertLoadTypeToNavigationType(uint32_t aLoadType)
 
 static nsISHEntry* GetRootSHEntry(nsISHEntry *entry);
 
+static void
+AdjustAlwaysOpenPrivateDocShellCount()
+{
+#ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+    nsCOMPtr<nsIAppShellService> appShell
+      (do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
+    bool hasHiddenPrivateWindow = false;
+    if (appShell) {
+      appShell->GetHasHiddenPrivateWindow(&hasHiddenPrivateWindow);
+    }
+    gNumberOfAlwaysOpenPrivateDocShells = hasHiddenPrivateWindow ? 1 : 0;
+#endif
+}
+
 static void
 IncreasePrivateDocShellCount()
 {
+    AdjustAlwaysOpenPrivateDocShellCount();
+
     gNumberOfPrivateDocShells++;
-    if (gNumberOfPrivateDocShells > kNumberOfAlwaysOpenPrivateDocShells + 1 ||
+    if (gNumberOfPrivateDocShells > gNumberOfAlwaysOpenPrivateDocShells + 1 ||
         XRE_GetProcessType() != GeckoProcessType_Content) {
         return;
     }
@@ -704,9 +723,11 @@ IncreasePrivateDocShellCount()
 static void
 DecreasePrivateDocShellCount()
 {
+    AdjustAlwaysOpenPrivateDocShellCount();
+
     MOZ_ASSERT(gNumberOfPrivateDocShells > 0);
     gNumberOfPrivateDocShells--;
-    if (gNumberOfPrivateDocShells == kNumberOfAlwaysOpenPrivateDocShells)
+    if (gNumberOfPrivateDocShells == gNumberOfAlwaysOpenPrivateDocShells)
     {
         if (XRE_GetProcessType() == GeckoProcessType_Content) {
             mozilla::dom::ContentChild* cc = mozilla::dom::ContentChild::GetSingleton();

toolkit/components/startup/nsAppStartup.cpp

@@ -314,19 +314,23 @@ nsAppStartup::Quit(uint32_t aMode)
 
   // If we're considering quitting, we will only do so if:
   if (ferocity == eConsiderQuit) {
+#ifdef XP_MACOSX
+    nsCOMPtr<nsIAppShellService> appShell
+      (do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
+    bool hasHiddenPrivateWindow = false;
+    if (appShell) {
+      appShell->GetHasHiddenPrivateWindow(&hasHiddenPrivateWindow);
+    }
+    int32_t suspiciousCount = hasHiddenPrivateWindow ? 2 : 1;
+#endif
+
     if (mConsiderQuitStopper == 0) {
       // there are no windows...
       ferocity = eAttemptQuit;
     }
 #ifdef XP_MACOSX
-#ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
-    else if (mConsiderQuitStopper == 2) {
-#else
-    else if (mConsiderQuitStopper == 1) {
-#endif
+    else if (mConsiderQuitStopper == suspiciousCount) {
       // ... or there is only a hiddenWindow left, and it's useless:
-      nsCOMPtr<nsIAppShellService> appShell
-        (do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
 
       // Failure shouldn't be fatal, but will abort quit attempt:
       if (!appShell)
@@ -337,11 +341,15 @@ nsAppStartup::Quit(uint32_t aMode)
       nsCOMPtr<nsIXULWindow> hiddenWindow;
       appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
-      nsCOMPtr<nsIXULWindow> hiddenPrivateWindow;
-      appShell->GetHiddenPrivateWindow(getter_AddRefs(hiddenPrivateWindow));
       // If the remaining windows are useful, we won't quit:
+      nsCOMPtr<nsIXULWindow> hiddenPrivateWindow;
+      if (hasHiddenPrivateWindow) {
+        appShell->GetHiddenPrivateWindow(getter_AddRefs(hiddenPrivateWindow));
         if ((!hiddenWindow && !hiddenPrivateWindow) || usefulHiddenWindow)
           return NS_OK;
+      } else if (!hiddenWindow || usefulHiddenWindow) {
+        return NS_OK;
+      }
 #else
       // If the one window is useful, we won't quit:
       if (!hiddenWindow || usefulHiddenWindow)

xpfe/appshell/public/nsIAppShellService.idl

@@ -16,7 +16,7 @@ interface nsIAppShell;
 struct JSContext;
 %}
 
-[scriptable, uuid(76e6364a-5453-47c7-ad83-8c30eff20a75)]
+[scriptable, uuid(5c19ab54-67bf-46d0-ac5b-21abd9050c3b)]
 interface nsIAppShellService : nsISupports
 {
   /**
@@ -117,4 +117,10 @@ interface nsIAppShellService : nsISupports
    * @param aWindow you see the pattern
    */
   void unregisterTopLevelWindow(in nsIXULWindow aWindow);
+
+  /**
+   * Whether the hidden private window has been lazily created.
+   */
+  [noscript]
+  readonly attribute boolean hasHiddenPrivateWindow;
 };

xpfe/appshell/src/nsAppShellService.cpp

@@ -82,6 +82,22 @@ NS_IMPL_ISUPPORTS2(nsAppShellService,
 
 NS_IMETHODIMP
 nsAppShellService::CreateHiddenWindow()
+{
+  return CreateHiddenWindowHelper(false);
+}
+
+void
+nsAppShellService::EnsurePrivateHiddenWindow()
+{
+#ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+  if (!mHiddenPrivateWindow) {
+    CreateHiddenWindowHelper(true);
+  }
+#endif
+}
+
+nsresult
+nsAppShellService::CreateHiddenWindowHelper(bool aIsPrivate)
 {
   nsresult rv;
   int32_t initialHeight = 100, initialWidth = 100;
@@ -91,7 +107,11 @@ nsAppShellService::CreateHiddenWindow()
   nsAdoptingCString prefVal =
       Preferences::GetCString("browser.hiddenWindowChromeURL");
   const char* hiddenWindowURL = prefVal.get() ? prefVal.get() : DEFAULT_HIDDENWINDOW_URL;
+  if (aIsPrivate) {
+    hiddenWindowURL = DEFAULT_HIDDENWINDOW_URL;
+  } else {
     mApplicationProvidedHiddenWindow = prefVal.get() ? true : false;
+  }
 #else
   static const char hiddenWindowURL[] = DEFAULT_HIDDENWINDOW_URL;
   uint32_t    chromeMask =  nsIWebBrowserChrome::CHROME_ALL;
@@ -102,14 +122,16 @@ nsAppShellService::CreateHiddenWindow()
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsRefPtr<nsWebShellWindow> newWindow;
+  if (!aIsPrivate) {
     rv = JustCreateTopWindow(nullptr, url,
                              chromeMask, initialWidth, initialHeight,
                              true, getter_AddRefs(newWindow));
     NS_ENSURE_SUCCESS(rv, rv);
 
     mHiddenWindow.swap(newWindow);
-
+  }
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+  else {
     // Create the hidden private window
     chromeMask |= nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW;
 
@@ -119,6 +141,7 @@ nsAppShellService::CreateHiddenWindow()
     NS_ENSURE_SUCCESS(rv, rv);
 
     mHiddenPrivateWindow.swap(newWindow);
+  }
 #endif
 
   // RegisterTopLevelWindow(newWindow); -- Mac only
@@ -446,6 +469,8 @@ nsAppShellService::GetHiddenPrivateWindow(nsIXULWindow **aWindow)
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
   NS_ENSURE_ARG_POINTER(aWindow);
 
+  EnsurePrivateHiddenWindow();
+
   *aWindow = mHiddenPrivateWindow;
   NS_IF_ADDREF(*aWindow);
   return *aWindow ? NS_OK : NS_ERROR_FAILURE;
@@ -458,6 +483,8 @@ NS_IMETHODIMP
 nsAppShellService::GetHiddenPrivateDOMWindow(nsIDOMWindow **aWindow)
 {
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+  EnsurePrivateHiddenWindow();
+
   nsresult rv;
   nsCOMPtr<nsIDocShell> docShell;
   NS_ENSURE_TRUE(mHiddenPrivateWindow, NS_ERROR_FAILURE);
@@ -476,6 +503,19 @@ nsAppShellService::GetHiddenPrivateDOMWindow(nsIDOMWindow **aWindow)
 #endif
 }
 
+NS_IMETHODIMP
+nsAppShellService::GetHasHiddenPrivateWindow(bool* aHasPrivateWindow)
+{
+#ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
+  NS_ENSURE_ARG_POINTER(aHasPrivateWindow);
+
+  *aHasPrivateWindow = !!mHiddenPrivateWindow;
+  return NS_OK;
+#else
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
 NS_IMETHODIMP
 nsAppShellService::GetHiddenWindowAndJSContext(nsIDOMWindow **aWindow,
                                                JSContext    **aJSContext)

xpfe/appshell/src/nsAppShellService.h

@@ -32,6 +32,9 @@ public:
 protected:
   ~nsAppShellService();
 
+  nsresult CreateHiddenWindowHelper(bool aIsPrivate);
+  void EnsurePrivateHiddenWindow();
+
   nsresult JustCreateTopWindow(nsIXULWindow *aParent,
                                nsIURI *aUrl, 
                                uint32_t aChromeMask,