Replacing most of web_task.h with base::Closure + base::WeakPtrFactory.

components/test_runner/mock_web_user_media_client.h

Index: components/test_runner/mock_web_user_media_client.h
diff --git a/components/test_runner/mock_web_user_media_client.h b/components/test_runner/mock_web_user_media_client.h
index dda0d4df31a92ae57a45abbba6f6e55b65801154..5649f796f1b0c5007be0eaf935327687c63cf0d1 100644
--- a/components/test_runner/mock_web_user_media_client.h
+++ b/components/test_runner/mock_web_user_media_client.h
@@ -6,7 +6,7 @@
 #define COMPONENTS_TEST_RUNNER_MOCK_WEB_USER_MEDIA_CLIENT_H_
 
 #include "base/macros.h"
-#include "components/test_runner/web_task.h"
+#include "base/memory/weak_ptr.h"
 #include "third_party/WebKit/public/web/WebUserMediaClient.h"
 
 namespace test_runner {
@@ -16,7 +16,7 @@ class WebTestDelegate;
 class MockWebUserMediaClient : public blink::WebUserMediaClient {
  public:
   explicit MockWebUserMediaClient(WebTestDelegate* delegate);
-  ~MockWebUserMediaClient() override {}
+  ~MockWebUserMediaClient() override;
 
   void requestUserMedia(const blink::WebUserMediaRequest&) override;
   void cancelUserMediaRequest(const blink::WebUserMediaRequest&) override;
@@ -24,13 +24,11 @@ class MockWebUserMediaClient : public blink::WebUserMediaClient {
   void cancelMediaDevicesRequest(const blink::WebMediaDevicesRequest&) override;
   void requestSources(const blink::WebMediaStreamTrackSourcesRequest&) override;
 
-  // Task related methods
-  WebTaskList* mutable_task_list() { return &task_list_; }
-
  private:
-  WebTaskList task_list_;
   WebTestDelegate* delegate_;
 
+  base::WeakPtrFactory<MockWebUserMediaClient> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(MockWebUserMediaClient);
 };