Implement Wheel Gesture Scrolling on OSX.

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 944 matching lines @@
     input_handler_manager->ObserveWheelEventAndResultOnMainThread(
         routing_id_, wheel_event, scroll_result);
   }
 }
 
 void RenderWidget::OnDidHandleKeyEvent() {
   if (owner_delegate_)
     owner_delegate_->RenderWidgetDidHandleKeyEvent();
 }
 
+void RenderWidget::ObserveGestureEventAndResult(

[Charlie Reis, 2016/03/09 22:49:17]

nit: Move above OnDidHandleKeyEvent.

[dtapuska, 2016/03/10 19:51:15]

Done.

+    const blink::WebGestureEvent& gesture_event,
+    const gfx::Vector2dF& unused_delta,
+    bool event_processed) {
+  if (!compositor_deps_->IsElasticOverscrollEnabled())
+    return;
+
+  cc::InputHandlerScrollResult scroll_result;
+  scroll_result.did_scroll = event_processed;
+  scroll_result.did_overscroll_root = !unused_delta.IsZero();
+  scroll_result.unused_scroll_delta = unused_delta;
+
+  RenderThreadImpl* render_thread = RenderThreadImpl::current();
+  InputHandlerManager* input_handler_manager =
+      render_thread ? render_thread->input_handler_manager() : NULL;
+  if (input_handler_manager) {
+    input_handler_manager->ObserveGestureEventAndResultOnMainThread(
+        routing_id_, gesture_event, scroll_result);
+  }
+}
+
 void RenderWidget::OnDidOverscroll(const DidOverscrollParams& params) {
   Send(new InputHostMsg_DidOverscroll(routing_id_, params));
 }
 
 void RenderWidget::OnInputEventAck(scoped_ptr<InputEventAck> input_event_ack) {
   Send(new InputHostMsg_HandleInputEvent_ACK(routing_id_, *input_event_ack));
 }
 
 void RenderWidget::NonBlockingInputEventHandled(
     blink::WebInputEvent::Type handled_type) {
@@ skipping 1175 matching lines @@
 }
 
 float RenderWidget::GetOriginalDeviceScaleFactor() const {
   return
       screen_metrics_emulator_ ?
       screen_metrics_emulator_->original_screen_info().deviceScaleFactor :
       device_scale_factor_;
 }
 
 }  // namespace content