Blimp Client: add support for tap gesture events

blimp/engine/session/blimp_engine_session.cc

 // Copyright 2015 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 "blimp/engine/session/blimp_engine_session.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
@@ skipping 371 matching lines @@
 
 void BlimpEngineSession::Reload(const int target_tab_id) {
   DVLOG(1) << "Reload in tab " << target_tab_id;
   web_contents_->GetController().Reload(true);
 }
 
 void BlimpEngineSession::OnWebGestureEvent(
     content::RenderWidgetHost* render_widget_host,
     std::unique_ptr<blink::WebGestureEvent> event) {
   TRACE_EVENT0("blimp", "BlimpEngineSession::OnWebGestureEvent");
-
+  DVLOG(2) << "OnWebGestureEvent: " << event->type;

[Kevin M, 2016/05/16 18:31:32]

As long as we are adding traces for this event, what about just pushing
event->type in as a trace ID?

[haibinlu, 2016/05/16 18:41:42]

but trace ID does not give a sequence of event types that lead to engine crash. 

[haibinlu, 2016/05/16 18:57:29]

done

   render_widget_host->ForwardGestureEvent(*event);
 }
 
 void BlimpEngineSession::OnCompositorMessageReceived(
     content::RenderWidgetHost* render_widget_host,
     const std::vector<uint8_t>& message) {
   TRACE_EVENT0("blimp", "BlimpEngineSession::OnCompositorMessageReceived");
 
   render_widget_host->HandleCompositorProto(message);
 }
@@ skipping 245 matching lines @@
 
   aura::Window* parent = window_tree_host_->window();
   aura::Window* content = web_contents_->GetNativeView();
   if (!parent->Contains(content))
     parent->AddChild(content);
   content->Show();
 }
 
 }  // namespace engine
 }  // namespace blimp