ui::Compositor needs a valid FrameSinkId even when it doesn't have ContextFactoryPrivate.

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 <stddef.h>
 
 #include <algorithm>
 #include <deque>
@@ skipping 28 matching lines @@
 #include "ui/compositor/dip_util.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animator_collection.h"
 #include "ui/gl/gl_switches.h"
 
 namespace {
 
 const double kDefaultRefreshRate = 60.0;
 const double kTestRefreshRate = 200.0;
 
+// TODO(mfomitchev, fsamuel): Look at removing this when transition from
+// SurfaceSequence to SurfaceReference is fully complete.
+// Used when ui::Compositor is created with null ContextFactoryPrivate.
+// Compositor needs a valid FrameSinkId, so that cc::SurfaceLayer can create
+// valid SurfaceSequences.
+constexpr cc::FrameSinkId kDefaultFrameSinkId(1, 1);
+
 }  // namespace
 
 namespace ui {
 
 CompositorLock::CompositorLock(Compositor* compositor)
     : compositor_(compositor) {
   if (compositor_->locks_will_time_out_) {
     compositor_->task_runner_->PostDelayedTask(
         FROM_HERE,
         base::Bind(&CompositorLock::CancelLock, AsWeakPtr()),
@@ skipping 19 matching lines @@
       context_factory_private_(context_factory_private),
       root_layer_(NULL),
       widget_(gfx::kNullAcceleratedWidget),
 #if defined(USE_AURA)
       window_(nullptr),
 #endif
       widget_valid_(false),
       compositor_frame_sink_requested_(false),
       frame_sink_id_(context_factory_private
                          ? context_factory_private->AllocateFrameSinkId()
-                         : cc::FrameSinkId()),
+                         : kDefaultFrameSinkId),
       task_runner_(task_runner),
       vsync_manager_(new CompositorVSyncManager()),
       device_scale_factor_(0.0f),
       locks_will_time_out_(true),
       compositor_lock_(NULL),
       layer_animator_collection_(this),
       weak_ptr_factory_(this) {
   if (context_factory_private) {
     context_factory_private->GetSurfaceManager()->RegisterFrameSinkId(
         frame_sink_id_);
@@ skipping 459 matching lines @@
   for (auto& observer : observer_list_)
     observer.OnCompositingLockStateChanged(this);
 }
 
 void Compositor::CancelCompositorLock() {
   if (compositor_lock_)
     compositor_lock_->CancelLock();
 }
 
 }  // namespace ui