Split surface id and simplify connecting to surfaces service

sky/viewer/document_view.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 "sky/viewer/document_view.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 138 matching lines @@
   double interval_sec = 1.0/60;
   blink::WebBeginFrameArgs web_begin_frame_args(
       frame_time_sec, deadline_sec, interval_sec);
   web_view_->beginFrame(web_begin_frame_args);
   web_view_->layout();
   blink::WebSize size = web_view_->size();
   root_layer_->SetSize(gfx::Size(size.width, size.height));
 }
 
 void DocumentView::OnSurfaceIdAvailable(mojo::SurfaceIdPtr surface_id) {
-  root_->SetSurfaceId(surface_id.Pass());
+  if (root_)

[jamesr, 2014/12/16 00:02:47]

this is not directly related, but fixes a flaky shutdown crash

[esprehn, 2014/12/16 00:51:11]

Wouldn't we want to shutdown the connection to surfaces service after
OnViewDestroyed instead? What frees the surface with this id?

[jamesr, 2014/12/16 00:56:09]

This isn't about controlling the surface, this is about communicating the ID
with the view manager.  At this point, if root_ is null then our app's part of
the view manager lib (including its connection to the view manager service) have
already gone down so there's nowhere to send the ID.

The surface itself is managed elsewhere.

[esprehn, 2014/12/16 01:23:57]

Why do we even get this message if everything is torn down?

+    root_->SetSurfaceId(surface_id.Pass());
 }
 
 void DocumentView::PaintContents(SkCanvas* canvas, const gfx::Rect& clip) {
   blink::WebRect rect(clip.x(), clip.y(), clip.width(), clip.height());
   web_view_->paint(canvas, rect);
 }
 
 void DocumentView::scheduleAnimation() {
   DCHECK(web_view_);
   layer_host_->SetNeedsAnimate();
@@ skipping 107 matching lines @@
 void DocumentView::StartDebuggerInspectorBackend() {
   if (!inspector_backend_) {
     inspector_host_.reset(new InspectorHostImpl(web_view_, shell_));
     inspector_backend_.reset(
         new inspector::InspectorBackendMojo(inspector_host_.get()));
   }
   inspector_backend_->Connect();
 }
 
 }  // namespace sky