Migrate PushMessagingClient to use GC mojo wrappers.

No behavior change. This CL reduces potential risks of use-after-free bugs.

Bug: 1049056
Change-Id: I666b8ade1cd0ea9043df7978a01eb4537fbbc713
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2109396
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755291}

third_party/blink/renderer/modules/push_messaging/push_messaging_client.cc

@@ -13,6 +13,7 @@
 #include "third_party/blink/public/platform/platform.h"
 #include "third_party/blink/public/web/web_local_frame.h"
 #include "third_party/blink/public/web/web_local_frame_client.h"
+#include "third_party/blink/renderer/core/frame/local_dom_window.h"
 #include "third_party/blink/renderer/core/frame/local_frame_client.h"
 #include "third_party/blink/renderer/modules/manifest/manifest_manager.h"
 #include "third_party/blink/renderer/modules/push_messaging/push_error.h"
@@ -30,7 +31,8 @@ namespace blink {
 const char PushMessagingClient::kSupplementName[] = "PushMessagingClient";
 
 PushMessagingClient::PushMessagingClient(LocalFrame& frame)
-    : Supplement<LocalFrame>(frame) {
+    : Supplement<LocalFrame>(frame),
+      push_messaging_manager_(frame.DomWindow()) {
   // This class will be instantiated for every page load (rather than on push
   // messaging use), so there's nothing to be done in this constructor.
 }
@@ -42,7 +44,7 @@ PushMessagingClient* PushMessagingClient::From(LocalFrame* frame) {
 }
 
 mojom::blink::PushMessaging* PushMessagingClient::GetPushMessagingRemote() {
-  if (!push_messaging_manager_) {
+  if (!push_messaging_manager_.is_bound()) {
     GetSupplementable()->GetBrowserInterfaceBroker().GetInterface(
         push_messaging_manager_.BindNewPipeAndPassReceiver(
             GetSupplementable()->GetTaskRunner(TaskType::kMiscPlatformAPI)));
@@ -76,6 +78,11 @@ void PushMessagingClient::Subscribe(
   }
 }
 
+void PushMessagingClient::Trace(Visitor* visitor) {
+  Supplement<LocalFrame>::Trace(visitor);
+  visitor->Trace(push_messaging_manager_);
+}
+
 void PushMessagingClient::DidGetManifest(
     ServiceWorkerRegistration* service_worker_registration,
     mojom::blink::PushSubscriptionOptionsPtr options,

third_party/blink/renderer/modules/push_messaging/push_messaging_client.h

@@ -9,11 +9,12 @@
 #include <memory>
 
 #include "base/macros.h"
-#include "mojo/public/cpp/bindings/remote.h"
 #include "third_party/blink/public/mojom/manifest/manifest.mojom-blink-forward.h"
 #include "third_party/blink/public/mojom/push_messaging/push_messaging.mojom-blink.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/modules/push_messaging/push_subscription_callbacks.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_wrapper_mode.h"
 #include "third_party/blink/renderer/platform/supplementable.h"
 
 namespace blink {
@@ -42,6 +43,7 @@ class PushMessagingClient final : public GarbageCollected<PushMessagingClient>,
                  PushSubscriptionOptions* options,
                  bool user_gesture,
                  std::unique_ptr<PushSubscriptionCallbacks> callbacks);
+  void Trace(Visitor*) override;
 
  private:
   // Returns an initialized PushMessaging service. A connection will be
@@ -65,7 +67,9 @@ class PushMessagingClient final : public GarbageCollected<PushMessagingClient>,
                     mojom::blink::PushRegistrationStatus status,
                     mojom::blink::PushSubscriptionPtr subscription);
 
-  mojo::Remote<mojom::blink::PushMessaging> push_messaging_manager_;
+  HeapMojoRemote<mojom::blink::PushMessaging,
+                 HeapMojoWrapperMode::kWithoutContextObserver>
+      push_messaging_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(PushMessagingClient);
 };