Migrate PushProvider to use GC mojo wrappers.

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

Bug: 1049056
Change-Id: I063d45ca3749e68751daa6d38f7e38080b333872
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2131971
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756216}

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

@@ -13,6 +13,7 @@
 #include "third_party/blink/renderer/modules/push_messaging/push_messaging_utils.h"
 #include "third_party/blink/renderer/modules/push_messaging/push_subscription.h"
 #include "third_party/blink/renderer/modules/push_messaging/push_subscription_options.h"
+#include "third_party/blink/renderer/platform/scheduler/public/thread_scheduler.h"
 #include "third_party/blink/renderer/platform/weborigin/kurl.h"
 #include "third_party/blink/renderer/platform/wtf/functional.h"
 
@@ -22,7 +23,8 @@ namespace blink {
 const char PushProvider::kSupplementName[] = "PushProvider";
 
 PushProvider::PushProvider(ServiceWorkerRegistration& registration)
-    : Supplement<ServiceWorkerRegistration>(registration) {}
+    : Supplement<ServiceWorkerRegistration>(registration),
+      push_messaging_manager_(nullptr) {}
 
 // static
 PushProvider* PushProvider::From(ServiceWorkerRegistration* registration) {
@@ -41,9 +43,11 @@ PushProvider* PushProvider::From(ServiceWorkerRegistration* registration) {
 
 // static
 mojom::blink::PushMessaging* PushProvider::GetPushMessagingRemote() {
-  if (!push_messaging_manager_) {
+  if (!push_messaging_manager_.is_bound()) {
     Platform::Current()->GetBrowserInterfaceBroker()->GetInterface(
-        push_messaging_manager_.BindNewPipeAndPassReceiver());
+        push_messaging_manager_.BindNewPipeAndPassReceiver(
+            GetSupplementable()->GetExecutionContext()->GetTaskRunner(
+                TaskType::kMiscPlatformAPI)));
   }
 
   return push_messaging_manager_.get();
@@ -122,6 +126,11 @@ void PushProvider::GetSubscription(
                 WTF::Passed(std::move(callbacks))));
 }
 
+void PushProvider::Trace(Visitor* visitor) {
+  visitor->Trace(push_messaging_manager_);
+  Supplement::Trace(visitor);
+}
+
 void PushProvider::DidGetSubscription(
     std::unique_ptr<PushSubscriptionCallbacks> callbacks,
     mojom::blink::PushGetRegistrationStatus status,

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

@@ -11,11 +11,12 @@
 #include "base/macros.h"
 #include "base/memory/scoped_refptr.h"
 #include "base/single_thread_task_runner.h"
-#include "mojo/public/cpp/bindings/remote.h"
 #include "third_party/blink/public/mojom/push_messaging/push_messaging.mojom-blink.h"
 #include "third_party/blink/public/mojom/push_messaging/push_messaging_status.mojom-blink-forward.h"
 #include "third_party/blink/renderer/modules/push_messaging/push_subscription_callbacks.h"
 #include "third_party/blink/renderer/modules/service_worker/service_worker_registration.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"
 #include "third_party/blink/renderer/platform/wtf/vector.h"
 
@@ -46,6 +47,8 @@ class PushProvider final : public GarbageCollected<PushProvider>,
   void Unsubscribe(std::unique_ptr<PushUnsubscribeCallbacks> callbacks);
   void GetSubscription(std::unique_ptr<PushSubscriptionCallbacks> callbacks);
 
+  void Trace(Visitor*) override;
+
  private:
   // Returns an initialized PushMessaging service. A connection will be
   // established after the first call to this method.
@@ -64,7 +67,9 @@ class PushProvider final : public GarbageCollected<PushProvider>,
                           mojom::blink::PushGetRegistrationStatus 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(PushProvider);
 };