Fall back to software mode if Aura can't create a GL context

ui/compositor/compositor.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 "ui/compositor/compositor.h"
 
 #include <algorithm>
 #include <deque>
 
 #include "base/bind.h"
@@ skipping 487 matching lines @@
 void Compositor::Layout() {
   // We're sending damage that will be addressed during this composite
   // cycle, so we don't need to schedule another composite to address it.
   disable_schedule_composite_ = true;
   if (root_layer_)
     root_layer_->SendDamagedRects();
   disable_schedule_composite_ = false;
 }
 
 scoped_ptr<cc::OutputSurface> Compositor::CreateOutputSurface(bool fallback) {
-  return ContextFactory::GetInstance()->CreateOutputSurface(this);
+  return ContextFactory::GetInstance()->CreateOutputSurface(this, fallback);
 }
 
 void Compositor::DidCommit() {
   DCHECK(!IsLocked());
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingDidCommit(this));
 }
 
 void Compositor::DidCommitAndDrawFrame() {
@@ skipping 97 matching lines @@
     // CompositorObservers to be notified before starting another
     // draw cycle.
     ScheduleDraw();
   }
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingEnded(this));
 }
 
 }  // namespace ui