overscroll-aura: Discard synthetic mouse-move events during a trackpad overscroll.

content/browser/renderer_host/render_widget_host_view_aura.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/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "content/browser/renderer_host/backing_store_aura.h"
 #include "content/browser/renderer_host/dip_util.h"
+#include "content/browser/renderer_host/overscroll_controller.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/ui_events_helper.h"
 #include "content/browser/renderer_host/web_input_event_aura.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/view_messages.h"
 #include "content/port/browser/render_widget_host_view_port.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 1536 matching lines @@
       }
 
       // Forward event to renderer.
       if (CanRendererHandleEvent(event))
         host_->ForwardMouseEvent(mouse_event);
     }
 
     return ui::ER_UNHANDLED;
   }
 
+  // If the overscroll controller is active, then drop all synthetic move events
+  // on the floor.

[sky, 2012/11/19 16:25:01]

Document why you do this.

[sadrul, 2012/11/19 16:34:35]

Done.

+  if (host_->overscroll_controller() &&
+      host_->overscroll_controller()->overscroll_mode() != OVERSCROLL_NONE &&
+      event->type() == ui::ET_MOUSE_MOVED &&
+      (event->flags() & ui::EF_IS_SYNTHESIZED)) {
+    return ui::ER_CONSUMED;
+  }
+
   if (event->type() == ui::ET_MOUSEWHEEL) {
     WebKit::WebMouseWheelEvent mouse_wheel_event =
         MakeWebMouseWheelEvent(static_cast<ui::MouseWheelEvent*>(event));
     if (mouse_wheel_event.deltaX != 0 || mouse_wheel_event.deltaY != 0)
       host_->ForwardWheelEvent(mouse_wheel_event);
   } else if (CanRendererHandleEvent(event)) {
     WebKit::WebMouseEvent mouse_event = MakeWebMouseEvent(event);
     ModifyEventMovementAndCoords(&mouse_event);
     host_->ForwardMouseEvent(mouse_event);
   }
@@ skipping 397 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content