Bug 1114507 - Part 3: Remove PContetBridge channel when grandchild-process is killed. r=kanru

dom/ipc/ContentBridgeChild.cpp

@@ -12,7 +12,6 @@
 #include "mozilla/dom/ipc/BlobChild.h"
 #include "mozilla/jsipc/CrossProcessObjectWrappers.h"
 #include "mozilla/ipc/InputStreamUtils.h"
-#include "nsIObserverService.h"
 
 using namespace mozilla::ipc;
 using namespace mozilla::jsipc;
@@ -21,8 +20,7 @@ namespace mozilla {
 namespace dom {
 
 NS_IMPL_ISUPPORTS(ContentBridgeChild,
-                  nsIContentChild,
-                  nsIObserver)
+                  nsIContentChild)
 
 ContentBridgeChild::ContentBridgeChild(Transport* aTransport)
   : mTransport(aTransport)
@@ -36,10 +34,6 @@ ContentBridgeChild::~ContentBridgeChild()
 void
 ContentBridgeChild::ActorDestroy(ActorDestroyReason aWhy)
 {
-  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-  if (os) {
-    os->RemoveObserver(this, "content-child-shutdown");
-  }
   MessageLoop::current()->PostTask(
     FROM_HERE,
     NewRunnableMethod(this, &ContentBridgeChild::DeferredDestroy));
@@ -55,11 +49,6 @@ ContentBridgeChild::Create(Transport* aTransport, ProcessId aOtherPid)
   DebugOnly<bool> ok = bridge->Open(aTransport, aOtherPid, XRE_GetIOMessageLoop());
   MOZ_ASSERT(ok);
 
-  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-  if (os) {
-    os->AddObserver(bridge, "content-child-shutdown", false);
-  }
-
   return bridge;
 }
 
@@ -180,16 +169,5 @@ ContentBridgeChild::DeallocPBlobChild(PBlobChild* aActor)
   return nsIContentChild::DeallocPBlobChild(aActor);
 }
 
-NS_IMETHODIMP
-ContentBridgeChild::Observe(nsISupports* aSubject,
-                             const char* aTopic,
-                             const char16_t* aData)
-{
-  if (!strcmp(aTopic, "content-child-shutdown")) {
-    Close();
-  }
-  return NS_OK;
-}
-
 } // namespace dom
 } // namespace mozilla

dom/ipc/ContentBridgeChild.h

@@ -9,20 +9,17 @@
 
 #include "mozilla/dom/PContentBridgeChild.h"
 #include "mozilla/dom/nsIContentChild.h"
-#include "nsIObserver.h"
 
 namespace mozilla {
 namespace dom {
 
 class ContentBridgeChild final : public PContentBridgeChild
                                , public nsIContentChild
-                               , public nsIObserver
 {
 public:
   explicit ContentBridgeChild(Transport* aTransport);
 
   NS_DECL_ISUPPORTS
-  NS_DECL_NSIOBSERVER
 
   static ContentBridgeChild*
   Create(Transport* aTransport, ProcessId aOtherProcess);

dom/ipc/ContentBridgeParent.cpp

@@ -163,6 +163,17 @@ ContentBridgeParent::DeallocPBrowserParent(PBrowserParent* aParent)
   return nsIContentParent::DeallocPBrowserParent(aParent);
 }
 
+void
+ContentBridgeParent::NotifyTabDestroyed()
+{
+  int32_t numLiveTabs = ManagedPBrowserParent().Length();
+  if (numLiveTabs == 1) {
+    MessageLoop::current()->PostTask(
+      FROM_HERE,
+      NewRunnableMethod(this, &ContentBridgeParent::Close));
+  }
+}
+
 // This implementation is identical to ContentParent::GetCPOWManager but we can't
 // move it to nsIContentParent because it calls ManagedPJavaScriptParent() which
 // only exists in PContentParent and PContentBridgeParent.

dom/ipc/ContentBridgeParent.h

@@ -28,6 +28,8 @@ public:
 
   virtual void ActorDestroy(ActorDestroyReason aWhy) override;
   void DeferredDestroy();
+  virtual bool IsContentBridgeParent() override { return true; }
+  void NotifyTabDestroyed();
 
   static ContentBridgeParent*
   Create(Transport* aTransport, ProcessId aOtherProcess);

dom/ipc/nsIContentParent.cpp

@@ -10,6 +10,7 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/dom/File.h"
 #include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/ContentBridgeParent.h"
 #include "mozilla/dom/PTabContext.h"
 #include "mozilla/dom/PermissionMessageUtils.h"
 #include "mozilla/dom/StructuredCloneUtils.h"
@@ -46,6 +47,13 @@ nsIContentParent::AsContentParent()
   return static_cast<ContentParent*>(this);
 }
 
+ContentBridgeParent*
+nsIContentParent::AsContentBridgeParent()
+{
+  MOZ_ASSERT(IsContentBridgeParent());
+  return static_cast<ContentBridgeParent*>(this);
+}
+
 PJavaScriptParent*
 nsIContentParent::AllocPJavaScriptParent()
 {

dom/ipc/nsIContentParent.h

@@ -38,6 +38,7 @@ class BlobConstructorParams;
 class BlobImpl;
 class BlobParent;
 class ContentParent;
+class ContentBridgeParent;
 class IPCTabContext;
 class PBlobParent;
 class PBrowserParent;
@@ -77,6 +78,8 @@ public:
 
   virtual bool IsContentParent() { return false; }
   ContentParent* AsContentParent();
+  virtual bool IsContentBridgeParent() { return false; }
+  ContentBridgeParent* AsContentBridgeParent();
 
 protected: // methods
   bool CanOpenBrowser(const IPCTabContext& aContext);