bug 1257287 - add nsIDocShell.tabChild r=smaug

accessible/base/DocManager.cpp

@@ -499,7 +499,7 @@ DocManager::CreateDocOrRootAccessible(nsIDocument* aDocument)
     if (IPCAccessibilityActive()) {
       nsIDocShell* docShell = aDocument->GetDocShell();
       if (docShell) {
-        nsCOMPtr<nsITabChild> tabChild = do_GetInterface(docShell);
+        nsCOMPtr<nsITabChild> tabChild = docShell->GetTabChild();
 
         // XXX We may need to handle the case that we don't have a tab child
         // differently.  It may be that this will cause us to fail to notify

docshell/base/nsDocShell.cpp

@@ -1047,14 +1047,8 @@ nsDocShell::GetInterface(const nsIID& aIID, void** aSink)
       return treeOwner->QueryInterface(aIID, aSink);
     }
   } else if (aIID.Equals(NS_GET_IID(nsITabChild))) {
-    nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
-    nsresult rv = GetTreeOwner(getter_AddRefs(treeOwner));
-    if (NS_SUCCEEDED(rv) && treeOwner) {
-      nsCOMPtr<nsIInterfaceRequestor> ir = do_QueryInterface(treeOwner);
-      if (ir) {
-        return ir->GetInterface(aIID, aSink);
-      }
-    }
+    *aSink = GetTabChild().take();
+    return *aSink ? NS_OK : NS_ERROR_FAILURE;
   } else if (aIID.Equals(NS_GET_IID(nsIContentFrameMessageManager))) {
     nsCOMPtr<nsITabChild> tabChild =
       do_GetInterface(static_cast<nsIDocShell*>(this));
@@ -14364,3 +14358,18 @@ nsDocShell::GetEditingSession(nsIEditingSession** aEditSession)
   mEditorData->GetEditingSession(aEditSession);
   return *aEditSession ? NS_OK : NS_ERROR_FAILURE;
 }
+
+NS_IMETHODIMP
+nsDocShell::GetScriptableTabChild(nsITabChild** aTabChild)
+{
+  *aTabChild = GetTabChild().take();
+  return *aTabChild ? NS_OK : NS_ERROR_FAILURE;
+}
+
+already_AddRefed<nsITabChild>
+nsDocShell::GetTabChild()
+{
+  nsCOMPtr<nsIDocShellTreeOwner> owner(mTreeOwner);
+  nsCOMPtr<nsITabChild> tc = do_GetInterface(owner);
+  return tc.forget();
+}

docshell/base/nsIDocShell.idl

@@ -41,6 +41,8 @@ interface nsIPrivacyTransitionObserver;
 interface nsIReflowObserver;
 interface nsIScrollObserver;
 interface nsITabParent;
+interface nsITabChild;
+native TabChildRef(already_AddRefed<nsITabChild>);
 
 typedef unsigned long nsLoadFlags;
 
@@ -1097,4 +1099,10 @@ interface nsIDocShell : nsIDocShellTreeItem
    * The editing session for this docshell.
    */
   readonly attribute nsIEditingSession editingSession;
+
+  /**
+   * The tab child for this docshell.
+   */
+  [binaryname(ScriptableTabChild)] readonly attribute nsITabChild tabChild;
+  [noscript,notxpcom,nostdcall] TabChildRef GetTabChild();
 };

dom/base/nsCCUncollectableMarker.cpp

@@ -303,7 +303,8 @@ MarkWindowList(nsISimpleEnumerator* aWindowList, bool aCleanupJS,
 
       MarkDocShell(rootDocShell, aCleanupJS, aPrepareForCC);
 
-      nsCOMPtr<nsITabChild> tabChild = do_GetInterface(rootDocShell);
+      nsCOMPtr<nsITabChild> tabChild =
+        rootDocShell ? rootDocShell->GetTabChild() : nullptr;
       if (tabChild) {
         nsCOMPtr<nsIContentFrameMessageManager> mm;
         tabChild->GetMessageManager(getter_AddRefs(mm));

dom/base/nsFocusManager.cpp

@@ -869,9 +869,11 @@ nsFocusManager::WindowShown(mozIDOMWindowProxy* aWindow, bool aNeedsFocus)
     }
   }
 
-  if (nsCOMPtr<nsITabChild> child = do_GetInterface(window->GetDocShell())) {
-    bool active = static_cast<TabChild*>(child.get())->ParentIsActive();
-    ActivateOrDeactivate(window, active);
+  if (nsIDocShell* docShell = window->GetDocShell()) {
+    if (nsCOMPtr<nsITabChild> child = docShell->GetTabChild()) {
+      bool active = static_cast<TabChild*>(child.get())->ParentIsActive();
+      ActivateOrDeactivate(window, active);
+    }
   }
 
   if (mFocusedWindow != window)
@@ -1632,7 +1634,7 @@ nsFocusManager::Blur(nsPIDOMWindowOuter* aWindowToClear,
       if (aAdjustWidgets && objectFrame && !sTestMode) {
         if (XRE_IsContentProcess()) {
           // set focus to the top level window via the chrome process.
-          nsCOMPtr<nsITabChild> tabChild = do_GetInterface(docShell);
+          nsCOMPtr<nsITabChild> tabChild = docShell->GetTabChild();
           if (tabChild) {
             static_cast<TabChild*>(tabChild.get())->SendDispatchFocusToTopLevelWindow();
           }

dom/base/nsGlobalWindow.cpp

@@ -9061,9 +9061,12 @@ nsresult
 nsGlobalWindow::UpdateCommands(const nsAString& anAction, nsISelection* aSel, int16_t aReason)
 {
   // If this is a child process, redirect to the parent process.
-  if (nsCOMPtr<nsITabChild> child = do_GetInterface(GetDocShell())) {
-    nsContentUtils::AddScriptRunner(new ChildCommandDispatcher(this, child, anAction));
-    return NS_OK;
+  if (nsIDocShell* docShell = GetDocShell()) {
+    if (nsCOMPtr<nsITabChild> child = docShell->GetTabChild()) {
+      nsContentUtils::AddScriptRunner(new ChildCommandDispatcher(this, child,
+                                                                 anAction));
+      return NS_OK;
+    }
   }
 
   nsPIDOMWindowOuter *rootWindow = nsGlobalWindow::GetPrivateRoot();
@@ -10685,7 +10688,8 @@ nsGlobalWindow::ShowSlowScriptDialog()
       ProcessHangMonitor::Get()) {
     ProcessHangMonitor::SlowScriptAction action;
     RefPtr<ProcessHangMonitor> monitor = ProcessHangMonitor::Get();
-    nsCOMPtr<nsITabChild> child = do_GetInterface(GetDocShell());
+    nsIDocShell* docShell = GetDocShell();
+    nsCOMPtr<nsITabChild> child = docShell ? docShell->GetTabChild() : nullptr;
     action = monitor->NotifySlowScript(child,
                                        filename.get(),
                                        lineno);

dom/events/EventStateManager.cpp

@@ -981,7 +981,9 @@ EventStateManager::ExecuteAccessKey(nsTArray<uint32_t>& aAccessCharCodes,
         if (focusChanged && aIsTrustedEvent) {
           // If this is a child process, inform the parent that we want the focus, but
           // pass false since we don't want to change the window order.
-          nsCOMPtr<nsITabChild> child = do_GetInterface(mPresContext->GetDocShell());
+          nsIDocShell* docShell = mPresContext->GetDocShell();
+          nsCOMPtr<nsITabChild> child =
+            docShell ? docShell->GetTabChild() : nullptr;
           if (child) {
             child->SendRequestFocus(false);
           }

dom/ipc/TabChild.h

@@ -512,7 +512,11 @@ public:
   static inline TabChild*
   GetFrom(nsIDocShell* aDocShell)
   {
-    nsCOMPtr<nsITabChild> tc = do_GetInterface(aDocShell);
+    if (!aDocShell) {
+      return nullptr;
+    }
+
+    nsCOMPtr<nsITabChild> tc = aDocShell->GetTabChild();
     return static_cast<TabChild*>(tc.get());
   }
 

embedding/components/printingui/ipc/nsPrintingProxy.cpp

@@ -73,23 +73,20 @@ nsPrintingProxy::ShowPrintDialog(mozIDOMWindowProxy *parent,
   NS_ENSURE_ARG(webBrowserPrint);
   NS_ENSURE_ARG(printSettings);
 
-  // Get the root docshell owner of this nsIDOMWindow, which
-  // should map to a TabChild, which we can then pass up to
+  // Get the TabChild for this nsIDOMWindow, which we can then pass up to
   // the parent.
   nsCOMPtr<nsPIDOMWindowOuter> pwin = nsPIDOMWindowOuter::From(parent);
   NS_ENSURE_STATE(pwin);
   nsCOMPtr<nsIDocShell> docShell = pwin->GetDocShell();
   NS_ENSURE_STATE(docShell);
-  nsCOMPtr<nsIDocShellTreeOwner> owner;
-  nsresult rv = docShell->GetTreeOwner(getter_AddRefs(owner));
-  NS_ENSURE_SUCCESS(rv, rv);
 
-  nsCOMPtr<nsITabChild> tabchild = do_GetInterface(owner);
+  nsCOMPtr<nsITabChild> tabchild = docShell->GetTabChild();
   NS_ENSURE_STATE(tabchild);
 
   TabChild* pBrowser = static_cast<TabChild*>(tabchild.get());
 
   // Next, serialize the nsIWebBrowserPrint and nsIPrintSettings we were given.
+  nsresult rv = NS_OK;
   nsCOMPtr<nsIPrintOptions> po =
     do_GetService("@mozilla.org/gfx/printsettings-service;1", &rv);
   NS_ENSURE_SUCCESS(rv, rv);
@@ -134,17 +131,13 @@ nsPrintingProxy::ShowProgress(mozIDOMWindowProxy*      parent,
   NS_ENSURE_ARG(printProgressParams);
   NS_ENSURE_ARG(notifyOnOpen);
 
-  // Get the root docshell owner of this nsIDOMWindow, which
-  // should map to a TabChild, which we can then pass up to
+  // Get the TabChild for this nsIDOMWindow, which we can then pass up to
   // the parent.
   nsCOMPtr<nsPIDOMWindowOuter> pwin = nsPIDOMWindowOuter::From(parent);
   NS_ENSURE_STATE(pwin);
   nsCOMPtr<nsIDocShell> docShell = pwin->GetDocShell();
   NS_ENSURE_STATE(docShell);
-  nsCOMPtr<nsIDocShellTreeOwner> owner;
-  nsresult rv = docShell->GetTreeOwner(getter_AddRefs(owner));
-  NS_ENSURE_SUCCESS(rv, rv);
-  nsCOMPtr<nsITabChild> tabchild = do_GetInterface(owner);
+  nsCOMPtr<nsITabChild> tabchild = docShell->GetTabChild();
   TabChild* pBrowser = static_cast<TabChild*>(tabchild.get());
 
   RefPtr<PrintProgressDialogChild> dialogChild =
@@ -152,6 +145,7 @@ nsPrintingProxy::ShowProgress(mozIDOMWindowProxy*      parent,
 
   SendPPrintProgressDialogConstructor(dialogChild);
 
+  nsresult rv = NS_OK;
   mozilla::Unused << SendShowProgress(pBrowser, dialogChild,
                                       isForPrinting, notifyOnOpen, &rv);
   if (NS_FAILED(rv)) {

uriloader/prefetch/OfflineCacheUpdateChild.cpp

@@ -379,18 +379,13 @@ OfflineCacheUpdateChild::Schedule()
     NS_ASSERTION(mWindow, "Window must be provided to the offline cache update child");
 
     nsCOMPtr<nsPIDOMWindowInner> window = mWindow.forget();
-    nsIDocShell *docshell = window->GetDocShell();
-
-    nsCOMPtr<nsIDocShellTreeItem> item = do_QueryInterface(docshell);
-    if (!item) {
+    nsCOMPtr<nsIDocShell >docshell = window->GetDocShell();
+    if (!docshell) {
       NS_WARNING("doc shell tree item is null");
       return NS_ERROR_FAILURE;
     }
 
-    nsCOMPtr<nsIDocShellTreeOwner> owner;
-    item->GetTreeOwner(getter_AddRefs(owner));
-
-    nsCOMPtr<nsITabChild> tabchild = do_GetInterface(owner);
+    nsCOMPtr<nsITabChild> tabchild = docshell->GetTabChild();
     // because owner implements nsITabChild, we can assume that it is
     // the one and only TabChild.
     TabChild* child = tabchild ? static_cast<TabChild*>(tabchild.get()) : nullptr;