Dispatch scroll events as mouse wheel events in mus.

components/mus/ws/platform_display.cc

 // Copyright 2014 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 "components/mus/ws/platform_display.h"
 
 #include "base/numerics/safe_conversions.h"
 #include "build/build_config.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/copy_output_request.h"
@@ skipping 340 matching lines @@
 void DefaultPlatformDisplay::OnBoundsChanged(const gfx::Rect& new_bounds) {
   UpdateMetrics(new_bounds.size(), metrics_.device_pixel_ratio);
 }
 
 void DefaultPlatformDisplay::OnDamageRect(const gfx::Rect& damaged_region) {
   dirty_rect_.Union(damaged_region);
   WantToDraw();
 }
 
 void DefaultPlatformDisplay::DispatchEvent(ui::Event* event) {
-  if (event->IsMouseEvent() && !event->IsMouseWheelEvent()) {
+  if (event->IsScrollEvent()) {
+    // TODO(moshayedi): crbug.com/602859. Dispatch scroll events as
+    // they are once we have proper support for scroll events.
+    delegate_->OnEvent(ui::MouseWheelEvent(*event->AsScrollEvent()));
+  } else if (event->IsMouseEvent() && !event->IsMouseWheelEvent()) {
     delegate_->OnEvent(ui::PointerEvent(*event->AsMouseEvent()));
   } else if (event->IsTouchEvent()) {
     delegate_->OnEvent(ui::PointerEvent(*event->AsTouchEvent()));
   } else {
     delegate_->OnEvent(*event);
   }
 
 #if defined(USE_X11) || defined(USE_OZONE)
   // We want to emulate the WM_CHAR generation behaviour of Windows.
   //
@@ skipping 55 matching lines @@
 
 void DefaultPlatformDisplay::RequestCopyOfOutput(
     scoped_ptr<cc::CopyOutputRequest> output_request) {
   if (top_level_display_client_)
     top_level_display_client_->RequestCopyOfOutput(std::move(output_request));
 }
 
 }  // namespace ws
 
 }  // namespace mus