cc: Use HighResNow as timebase if it is fast and reliable

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 13 matching lines @@
 #include "cc/layers/layer.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/trees/layer_tree_host.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/compositor/compositor_observer.h"
 #include "ui/compositor/compositor_switches.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/reflector.h"
+#include "ui/gfx/frame_time.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/gl/gl_switches.h"
 #include "webkit/common/gpu/context_provider_in_process.h"
 #include "webkit/common/gpu/grcontext_for_webgraphicscontext3d.h"
 #include "webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h"
 
 namespace {
 
@@ skipping 504 matching lines @@
     delete g_compositor_thread;
     g_compositor_thread = NULL;
   }
 
   DCHECK(g_compositor_initialized) << "Compositor::Initialize() didn't happen.";
   g_compositor_initialized = false;
 }
 
 void Compositor::ScheduleDraw() {
   if (g_compositor_thread) {
-    host_->Composite(base::TimeTicks::Now());
+    host_->Composite(gfx::FrameTime::Now());
   } else if (!defer_draw_scheduling_) {
     defer_draw_scheduling_ = true;
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(&Compositor::Draw, schedule_draw_factory_.GetWeakPtr()));
   }
 }
 
 void Compositor::SetRootLayer(Layer* root_layer) {
   if (root_layer_ == root_layer)
@@ skipping 27 matching lines @@
 
   if (!root_layer_)
     return;
 
   last_started_frame_++;
   PendingSwap pending_swap(DRAW_SWAP, posted_swaps_.get());
   if (!IsLocked()) {
     // TODO(nduca): Temporary while compositor calls
     // compositeImmediately() directly.
     Layout();
-    host_->Composite(base::TimeTicks::Now());
+    host_->Composite(gfx::FrameTime::Now());
 
 #if defined(OS_WIN)
     // While we resize, we are usually a few frames behind. By blocking
     // the UI thread here we minize the area that is mis-painted, specially
     // in the non-client area. See RenderWidgetHostViewAura::SetBounds for
     // more details and bug 177115.
     if (next_draw_is_resize_ && (last_ended_frame_ > 1)) {
       next_draw_is_resize_ = false;
       host_->FinishAllRendering();
     }
@@ skipping 116 matching lines @@
 }
 
 void Compositor::DidCommit() {
   DCHECK(!IsLocked());
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingDidCommit(this));
 }
 
 void Compositor::DidCommitAndDrawFrame() {
-  base::TimeTicks start_time = base::TimeTicks::Now();
+  base::TimeTicks start_time = gfx::FrameTime::Now();
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingStarted(this, start_time));
 }
 
 void Compositor::DidCompleteSwapBuffers() {
   DCHECK(g_compositor_thread);
   NotifyEnd();
 }
 
@@ skipping 53 matching lines @@
     // CompositorObservers to be notified before starting another
     // draw cycle.
     ScheduleDraw();
   }
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingEnded(this));
 }
 
 }  // namespace ui