Add a new API to create a surfaceless GLSurface for Ozone

ui/ozone/platform/dri/dri_vsync_provider.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 "ui/ozone/platform/dri/dri_vsync_provider.h"
 
 #include "base/time/time.h"
 #include "ui/ozone/platform/dri/dri_window_delegate.h"
 #include "ui/ozone/platform/dri/hardware_display_controller.h"
 
 namespace ui {
 
 DriVSyncProvider::DriVSyncProvider(DriWindowDelegate* window_delegate)
     : window_delegate_(window_delegate) {
 }
 
 DriVSyncProvider::~DriVSyncProvider() {}
 
 void DriVSyncProvider::GetVSyncParameters(const UpdateVSyncCallback& callback) {
   HardwareDisplayController* controller = window_delegate_->GetController();
   if (!controller)
     return;
 
   // The value is invalid, so we can't update the parameters.
   if (controller->GetTimeOfLastFlip() == 0 ||
-      controller->get_mode().vrefresh == 0)
+      controller->get_mode().vrefresh == 0) {
+    callback.Run(base::TimeTicks(),

[dnicoara, 2015/02/23 22:48:26]

Why do you need this?

[achaulk, 2015/02/23 22:50:17]

Dropping the callback causes a deadlock

[dnicoara, 2015/02/24 16:46:53]

We should look into what's causing the deadlock. The VSyncProvider does not
guarantee that this is called in every scenario.

+                 base::TimeDelta::FromSecondsD(1.0f / 60.0f));
     return;
+  }
 
   // Stores the time of the last refresh.
   base::TimeTicks timebase =
       base::TimeTicks::FromInternalValue(controller->GetTimeOfLastFlip());
   // Stores the refresh rate.
   base::TimeDelta interval =
       base::TimeDelta::FromSeconds(1) / controller->get_mode().vrefresh;
 
   callback.Run(timebase, interval);
 }
 
 }  // namespace ui