phase based wheel scroll latching for mac

content/browser/renderer_host/render_widget_host_view_mac.h

 // 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurface.h>
 #include <stddef.h>
@@ skipping 469 matching lines @@
 
   // Returns the TextSelection information for the active widget. If
   // |is_guest_view_hack_| is true, then it will return the TextSelection
   // information for this RenderWidgetHostViewMac (which is serving as a
   // platform view for a guest).
   const TextInputManager::TextSelection* GetTextSelection();
 
   // Get the focused view that should be used for retrieving the text selection.
   RenderWidgetHostViewBase* GetFocusedViewForTextSelection();
 
+  base::OneShotTimer mouse_wheel_end_dispatch_timer_;
+
+  void SendSyntheticWheelEventWithPhaseEnded(
+      blink::WebMouseWheelEvent wheel_event,
+      bool should_route_event);
+  void StartMouseWheelEndDispatchTimer(blink::WebMouseWheelEvent wheel_event,
+                                       bool should_route_event);

[tdresser, 2017/05/25 19:34:48]

Since this is public, we might not want to refer to the implementation detail of
this starting the timer, but should refer to what the method does and when to
call it.

Something like QueueMouseWheelEnd, or MouseWheelMaybeFlinging or something like
that.

[sahel, 2017/05/26 18:03:25]

Done.

+
   // Returns the RenderWidgetHostDelegate corresponding to the currently focused
   // RenderWidgetHost. It is different from |render_widget_host_->delegate()|
   // when there are focused inner WebContentses on the page. Also, this method
   // can return nullptr; for instance when |render_widget_host_| becomes nullptr
   // in the destruction path of the WebContentsImpl.
   RenderWidgetHostDelegate* GetFocusedRenderWidgetHostDelegate();
 
  private:
   friend class RenderWidgetHostViewMacTest;
 
@@ skipping 67 matching lines @@
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_