sync compositor: Add output_surface_id

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 729 matching lines @@
         CreateGraphicsContext3D(gpu_channel_host.get()),
         RENDER_COMPOSITOR_CONTEXT);
     DCHECK(context_provider);
     worker_context_provider =
         RenderThreadImpl::current()->SharedWorkerContextProvider();
     if (!worker_context_provider) {
       // Cause the compositor to wait and try again.
       return nullptr;
     }
 
+    uint32_t output_surface_id = next_output_surface_id_++;
 #if defined(OS_ANDROID)
     if (SynchronousCompositorFactory* factory =
             SynchronousCompositorFactory::GetInstance()) {
       return factory->CreateOutputSurface(
-          routing_id(), frame_swap_message_queue_, context_provider,
-          worker_context_provider);
+          routing_id(), output_surface_id, frame_swap_message_queue_,
+          context_provider, worker_context_provider);
     } else if (RenderThreadImpl::current()->sync_compositor_message_filter()) {
       return make_scoped_ptr(new SynchronousCompositorOutputSurface(
           context_provider, worker_context_provider, routing_id(),
-          content::RenderThreadImpl::current()
-              ->sync_compositor_message_filter(),
+          output_surface_id, content::RenderThreadImpl::current()
+                                 ->sync_compositor_message_filter(),
           frame_swap_message_queue_));
     }
 #endif
   }
 
   uint32_t output_surface_id = next_output_surface_id_++;

[hush (inactive), 2016/03/09 02:36:17]

We can probably pull this line between 737 and 738.
Also, can we use ++next_output_surface_id_ instead? This way the valid id will
start with 1.

[boliu, 2016/03/09 02:39:44]

That can leave gaps if context creation fails. Not sure if that's ok or not.
Hmm... so 0 is a valid id, and there is no invalid id. I think this still works
out ok?

Don't want to be changing chrome behavior if I don't have to.

[hush (inactive), 2016/03/09 20:21:49]

Okay. Let's not change chrome behavior. 

   // Composite-to-mailbox is currently used for layout tests in order to cause
   // them to draw inside in the renderer to do the readback there. This should
   // no longer be the case when crbug.com/311404 is fixed.
   if (!RenderThreadImpl::current() ||
       !RenderThreadImpl::current()->layout_test_mode()) {
     DCHECK(compositor_deps_->GetCompositorImplThreadTaskRunner());
     return make_scoped_ptr(new DelegatedCompositorOutputSurface(
         routing_id(), output_surface_id, context_provider,
         worker_context_provider, frame_swap_message_queue_));
   }
@@ skipping 1382 matching lines @@
 }
 
 float RenderWidget::GetOriginalDeviceScaleFactor() const {
   return
       screen_metrics_emulator_ ?
       screen_metrics_emulator_->original_screen_info().deviceScaleFactor :
       device_scale_factor_;
 }
 
 }  // namespace content