Use observer pattern instead of sniffing SwapCompositorFrame IPC

content/browser/web_contents/web_contents_view_aura_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/web_contents/web_contents_view_aura.h"
 
 #include <stddef.h>
 #include <tuple>
 
 #include "base/command_line.h"
@@ skipping 220 matching lines @@
       test_url = GURL(embedded_test_server()->GetURL(url));
     NavigateToURL(shell(), test_url);
 
     WebContentsImpl* web_contents =
         static_cast<WebContentsImpl*>(shell()->web_contents());
     NavigationControllerImpl* controller = &web_contents->GetController();
 
     screenshot_manager_ = new ScreenshotTracker(controller);
     controller->SetScreenshotManager(base::WrapUnique(screenshot_manager_));
 
-    frame_watcher_ = new FrameWatcher();
-    frame_watcher_->AttachTo(shell()->web_contents());
+    frame_watcher_.Observe(shell()->web_contents());
   }
 
   void SetUpCommandLine(base::CommandLine* cmd) override {
     cmd->AppendSwitchASCII(switches::kTouchEventFeatureDetection,
                            switches::kTouchEventFeatureDetectionEnabled);
   }
 
   void TestOverscrollNavigation(bool touch_handler) {
     ASSERT_NO_FATAL_FAILURE(StartTestWithPage("/overscroll_navigation.html"));
     WebContentsImpl* web_contents =
@@ skipping 121 matching lines @@
         GetRenderViewHost()->GetWidget()->GetView());
   }
 
   InputEventMessageFilterWaitsForAcks* filter() {
     return filter_.get();
   }
 
   void WaitAFrame() {
     while (!GetRenderWidgetHost()->ScheduleComposite())
       GiveItSomeTime();
-    frame_watcher_->WaitFrames(1);
+    frame_watcher_.WaitFrames(1);
   }
 
  protected:
   ScreenshotTracker* screenshot_manager() { return screenshot_manager_; }
   void set_min_screenshot_interval(int interval_ms) {
     screenshot_manager_->SetScreenshotInterval(interval_ms);
   }
 
   void AddInputEventMessageFilter() {
     filter_ = new InputEventMessageFilterWaitsForAcks();
     GetRenderWidgetHost()->GetProcess()->AddFilter(filter_.get());
   }
 
  private:
   ScreenshotTracker* screenshot_manager_;
   scoped_refptr<InputEventMessageFilterWaitsForAcks> filter_;
-  scoped_refptr<FrameWatcher> frame_watcher_;
+  FrameWatcher frame_watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsViewAuraTest);
 };
 
 // Flaky on Windows: http://crbug.com/305722
 // The test frequently times out on Linux, too. See crbug.com/440043.
 #if defined(OS_WIN) || defined(OS_LINUX)
 #define MAYBE_OverscrollNavigation DISABLED_OverscrollNavigation
 #else
 #define MAYBE_OverscrollNavigation OverscrollNavigation
@@ skipping 710 matching lines @@
     details = sink->OnEventFromSource(&release);
     ASSERT_FALSE(details.dispatcher_destroyed);
     WaitAFrame();
 
     EXPECT_LT(0, tracker.num_overscroll_updates());
     EXPECT_FALSE(tracker.overscroll_completed());
   }
 }
 
 }  // namespace content