Implement Wheel Gesture Scrolling on OSX.

content/browser/renderer_host/input/non_blocking_event_browsertest.cc

 // Copyright 2016 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 <utility>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 95 matching lines @@
   }
 
   void DoWheelScroll() {
     EXPECT_EQ(0, GetScrollTop());
 
     int scrollHeight =
         ExecuteScriptAndExtractInt("document.documentElement.scrollHeight");
     EXPECT_EQ(1000, scrollHeight);
 
     scoped_refptr<FrameWatcher> frame_watcher(new FrameWatcher());
-    GetWidgetHost()->GetProcess()->AddFilter(frame_watcher.get());
+    frame_watcher->AttachTo(shell()->web_contents());
     scoped_refptr<InputMsgWatcher> input_msg_watcher(
         new InputMsgWatcher(GetWidgetHost(), blink::WebInputEvent::MouseWheel));
 
     GetWidgetHost()->ForwardWheelEvent(
         SyntheticWebMouseWheelEventBuilder::Build(10, 10, 0, -53, 0, true));
 
     // Runs until we get the InputMsgAck callback
     EXPECT_EQ(INPUT_EVENT_ACK_STATE_SET_NON_BLOCKING,
               input_msg_watcher->WaitForAck());
     frame_watcher->WaitFrames(1);
 
     // Expect that the compositor scrolled at least one pixel while the
     // main thread was in a busy loop.
     EXPECT_LT(0, frame_watcher->LastMetadata().root_scroll_offset.y());
   }
 
   void DoTouchScroll() {
     EXPECT_EQ(0, GetScrollTop());
 
     int scrollHeight =
         ExecuteScriptAndExtractInt("document.documentElement.scrollHeight");
     EXPECT_EQ(1000, scrollHeight);
 
     scoped_refptr<FrameWatcher> frame_watcher(new FrameWatcher());
-    GetWidgetHost()->GetProcess()->AddFilter(frame_watcher.get());
+    frame_watcher->AttachTo(shell()->web_contents());
 
     SyntheticSmoothScrollGestureParams params;
     params.gesture_source_type = SyntheticGestureParams::TOUCH_INPUT;
     params.anchor = gfx::PointF(50, 50);
     params.distances.push_back(gfx::Vector2d(0, -45));
 
     scoped_ptr<SyntheticSmoothScrollGesture> gesture(
         new SyntheticSmoothScrollGesture(params));
     GetWidgetHost()->QueueSyntheticGesture(
         std::move(gesture),
         base::Bind(&NonBlockingEventBrowserTest::OnSyntheticGestureCompleted,
                    base::Unretained(this)));
 
     // Expect that the compositor scrolled at least one pixel while the
     // main thread was in a busy loop.
     while (frame_watcher->LastMetadata().root_scroll_offset.y() <= 0)
       frame_watcher->WaitFrames(1);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NonBlockingEventBrowserTest);
 };
 
-// Disabled on MacOS because it doesn't support wheel gestures
-// just yet.
-#if defined(OS_MACOSX)
-#define MAYBE_MouseWheel DISABLED_MouseWheel
-#else
 // Also appears to be flaky under TSan. crbug.com/588199
 #if defined(THREAD_SANITIZER)
 #define MAYBE_MouseWheel DISABLED_MouseWheel
 #else
 #define MAYBE_MouseWheel MouseWheel
 #endif
-#endif
 IN_PROC_BROWSER_TEST_F(NonBlockingEventBrowserTest, MAYBE_MouseWheel) {
   LoadURL();
   DoWheelScroll();
 }
 
 // Disabled on MacOS because it doesn't support touch input.
 #if defined(OS_MACOSX)
 #define MAYBE_TouchStart DISABLED_TouchStart
 #else
 #define MAYBE_TouchStart TouchStart
 #endif
 IN_PROC_BROWSER_TEST_F(NonBlockingEventBrowserTest, MAYBE_TouchStart) {
   LoadURL();
   DoTouchScroll();
 }
 
 }  // namespace content