Refactors event dispatching of NativeViewport into its own interface

mojo/services/native_viewport/native_viewport_impl.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 "mojo/services/native_viewport/native_viewport_impl.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 75 matching lines @@
                             size_,
                             child_surface_id.To<cc::SurfaceId>()));
     if (widget_id_)
       viewport_surface_->SetWidgetId(widget_id_);
   }
   child_surface_id_ = child_surface_id.To<cc::SurfaceId>();
   if (viewport_surface_)
     viewport_surface_->SetChildId(child_surface_id_);
 }
 
+void NativeViewportImpl::SetEventDispatcher(
+    NativeViewportEventDispatcherPtr dispatcher) {
+  event_dispatcher_ = dispatcher.Pass();
+}
+
 void NativeViewportImpl::OnBoundsChanged(const gfx::Rect& bounds) {
   if (size_ == bounds.size())
     return;
 
   size_ = bounds.size();
 
   // Wait for the accelerated widget before telling the client of the bounds.
   if (create_callback_.is_null())
     ProcessOnBoundsChanged();
 }
 
 void NativeViewportImpl::OnAcceleratedWidgetAvailable(
     gfx::AcceleratedWidget widget) {
   widget_id_ = static_cast<uint64_t>(bit_cast<uintptr_t>(widget));
   // TODO(jamesr): Remove once everything is converted to surfaces.
   create_callback_.Run(widget_id_);
   create_callback_.reset();
   // Immediately tell the client of the size. The size may be wrong, if so we'll
   // get the right one in the next OnBoundsChanged() call.
   ProcessOnBoundsChanged();
   if (viewport_surface_)
     viewport_surface_->SetWidgetId(widget_id_);
 }
 
 bool NativeViewportImpl::OnEvent(ui::Event* ui_event) {
+  if (!event_dispatcher_.get())
+    return false;
+
   // Must not return early before updating capture.
   switch (ui_event->type()) {
     case ui::ET_MOUSE_PRESSED:
     case ui::ET_TOUCH_PRESSED:
       platform_viewport_->SetCapture();
       break;
     case ui::ET_MOUSE_RELEASED:
     case ui::ET_TOUCH_RELEASED:
       platform_viewport_->ReleaseCapture();
       break;
     default:
       break;
   }
 
   if (waiting_for_event_ack_ && IsRateLimitedEventType(ui_event))
     return false;
 
-  client()->OnEvent(
+  event_dispatcher_->OnEvent(
       Event::From(*ui_event),
       base::Bind(&NativeViewportImpl::AckEvent, weak_factory_.GetWeakPtr()));
   waiting_for_event_ack_ = true;
   return false;
 }
 
 void NativeViewportImpl::OnDestroyed() {
   client()->OnDestroyed();
 }
 
 void NativeViewportImpl::AckEvent() {
   waiting_for_event_ack_ = false;
 }
 
 void NativeViewportImpl::ProcessOnBoundsChanged() {
   client()->OnSizeChanged(Size::From(size_));
   if (viewport_surface_)
     viewport_surface_->SetSize(size_);
 }
 
 }  // namespace mojo