Bug 1510460 - Record the current WindowGlobal on ChromeBrowsingContext, r=farre

Differential Revision: https://phabricator.services.mozilla.com/D13156

docshell/base/ChromeBrowsingContext.cpp

@@ -74,6 +74,20 @@ void ChromeBrowsingContext::UnregisterWindowGlobal(
     WindowGlobalParent* aGlobal) {
   MOZ_ASSERT(mWindowGlobals.Contains(aGlobal), "Global not registered!");
   mWindowGlobals.RemoveEntry(aGlobal);
+
+  // Our current window global should be in our mWindowGlobals set. If it's not
+  // anymore, clear that reference.
+  if (aGlobal == mCurrentWindowGlobal) {
+    mCurrentWindowGlobal = nullptr;
+  }
+}
+
+void ChromeBrowsingContext::SetCurrentWindowGlobal(
+    WindowGlobalParent* aGlobal) {
+  MOZ_ASSERT(mWindowGlobals.Contains(aGlobal), "Global not registered!");
+
+  // TODO: This should probably assert that the processes match.
+  mCurrentWindowGlobal = aGlobal;
 }
 
 JSObject* ChromeBrowsingContext::WrapObject(JSContext* aCx,

docshell/base/ChromeBrowsingContext.h

@@ -41,6 +41,12 @@ class ChromeBrowsingContext final : public BrowsingContext {
   void RegisterWindowGlobal(WindowGlobalParent* aGlobal);
   void UnregisterWindowGlobal(WindowGlobalParent* aGlobal);
 
+  // The current active WindowGlobal.
+  WindowGlobalParent* GetCurrentWindowGlobal() const {
+    return mCurrentWindowGlobal;
+  }
+  void SetCurrentWindowGlobal(WindowGlobalParent* aGlobal);
+
   JSObject* WrapObject(JSContext* aCx,
                        JS::Handle<JSObject*> aGivenProto) override;
 
@@ -62,6 +68,7 @@ class ChromeBrowsingContext final : public BrowsingContext {
 
   // All live window globals within this browsing context.
   nsTHashtable<nsRefPtrHashKey<WindowGlobalParent>> mWindowGlobals;
+  RefPtr<WindowGlobalParent> mCurrentWindowGlobal;
 };
 
 }  // namespace dom

dom/base/nsGlobalWindowOuter.cpp

@@ -68,6 +68,7 @@
 #include "mozilla/intl/LocaleService.h"
 #include "WindowDestroyedEvent.h"
 #include "nsDocShellLoadState.h"
+#include "mozilla/dom/WindowGlobalChild.h"
 
 // Helper Classes
 #include "nsJSUtils.h"
@@ -1962,6 +1963,10 @@ nsresult nsGlobalWindowOuter::SetNewDocument(nsIDocument* aDocument,
     newInnerWindow->MigrateStateForDocumentOpen(currentInner);
   }
 
+  // Tell the WindowGlobalParent that it should become the current window global
+  // for our BrowsingContext if it isn't already.
+  mInnerWindow->GetWindowGlobalChild()->SendBecomeCurrentWindowGlobal();
+
   // We no longer need the old inner window.  Start its destruction if
   // its not being reused and clear our reference.
   if (doomCurrentInner) {

dom/chrome-webidl/BrowsingContext.webidl

@@ -21,4 +21,6 @@ interface BrowsingContext {
 [Exposed=Window, ChromeOnly]
 interface ChromeBrowsingContext : BrowsingContext {
   sequence<WindowGlobalParent> getWindowGlobals();
+
+  readonly attribute WindowGlobalParent? currentWindowGlobal;
 };

dom/chrome-webidl/WindowGlobalActors.webidl

@@ -13,6 +13,8 @@ interface WindowGlobalParent {
   readonly attribute boolean isInProcess;
   readonly attribute ChromeBrowsingContext browsingContext;
 
+  readonly attribute boolean isCurrentGlobal;
+
   readonly attribute unsigned long long innerWindowId;
   readonly attribute unsigned long long outerWindowId;
 
@@ -33,6 +35,8 @@ interface WindowGlobalChild {
   readonly attribute boolean isInProcess;
   readonly attribute BrowsingContext browsingContext;
 
+  readonly attribute boolean isCurrentGlobal;
+
   readonly attribute unsigned long long innerWindowId;
   readonly attribute unsigned long long outerWindowId;
 

dom/ipc/PWindowGlobal.ipdl

@@ -28,6 +28,9 @@ parent:
   /// Update the URI of the document in this WindowGlobal.
   async UpdateDocumentURI(nsIURI aUri);
 
+  /// Notify the parent that this PWindowGlobal is now the current global.
+  async BecomeCurrentWindowGlobal();
+
   async __delete__();
 };
 

dom/ipc/WindowGlobalChild.cpp

@@ -82,6 +82,12 @@ WindowGlobalChild::GetByInnerWindowId(uint64_t aInnerWindowId)
   return gWindowGlobalChildById->Get(aInnerWindowId);
 }
 
+bool
+WindowGlobalChild::IsCurrentGlobal()
+{
+  return !mIPCClosed && mWindowGlobal->IsCurrentInnerWindow();
+}
+
 already_AddRefed<WindowGlobalParent>
 WindowGlobalChild::GetParentActor()
 {

dom/ipc/WindowGlobalChild.h

@@ -53,6 +53,8 @@ public:
   uint64_t InnerWindowId() { return mInnerWindowId; }
   uint64_t OuterWindowId() { return mOuterWindowId; }
 
+  bool IsCurrentGlobal();
+
   // Get the other side of this actor if it is an in-process actor. Returns
   // |nullptr| if the actor has been torn down, or is not in-process.
   already_AddRefed<WindowGlobalParent> GetParentActor();

dom/ipc/WindowGlobalParent.cpp

@@ -124,6 +124,19 @@ WindowGlobalParent::RecvUpdateDocumentURI(nsIURI* aURI)
   return IPC_OK();
 }
 
+IPCResult
+WindowGlobalParent::RecvBecomeCurrentWindowGlobal()
+{
+  mBrowsingContext->SetCurrentWindowGlobal(this);
+  return IPC_OK();
+}
+
+bool
+WindowGlobalParent::IsCurrentGlobal()
+{
+  return !mIPCClosed && mBrowsingContext->GetCurrentWindowGlobal() == this;
+}
+
 void
 WindowGlobalParent::ActorDestroy(ActorDestroyReason aWhy)
 {

dom/ipc/WindowGlobalParent.h

@@ -71,6 +71,8 @@ public:
   uint64_t OuterWindowId() { return mOuterWindowId; }
   uint64_t InnerWindowId() { return mInnerWindowId; }
 
+  bool IsCurrentGlobal();
+
   // Create a WindowGlobalParent from over IPC. This method should not be called
   // from outside of the IPC constructors.
   WindowGlobalParent(const WindowGlobalInit& aInit, bool aInProcess);
@@ -86,6 +88,7 @@ public:
 protected:
   // IPC messages
   mozilla::ipc::IPCResult RecvUpdateDocumentURI(nsIURI* aURI) override;
+  mozilla::ipc::IPCResult RecvBecomeCurrentWindowGlobal() override;
 
   void ActorDestroy(ActorDestroyReason aWhy) override;