cc: Adding BeginFrameTracker object and removing Now() from LTHI.

cc/trees/layer_tree_host_impl_unittest.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/bind.h"
@@ skipping 153 matching lines @@
                               scoped_ptr<OutputSurface> output_surface) {
     host_impl_ = LayerTreeHostImpl::Create(settings,
                                            this,
                                            &proxy_,
                                            &stats_instrumentation_,
                                            shared_bitmap_manager_.get(),
                                            gpu_memory_buffer_manager_.get(),
                                            0);
     bool init = host_impl_->InitializeRenderer(output_surface.Pass());
     host_impl_->SetViewportSize(gfx::Size(10, 10));
+    // Set the BeginFrameArgs so that methods which use it are able to.
+    host_impl_->WillBeginImplFrame(
+        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
     return init;
   }
 
   void SetupRootLayerImpl(scoped_ptr<LayerImpl> root) {
     root->SetPosition(gfx::PointF());
     root->SetBounds(gfx::Size(10, 10));
     root->SetContentBounds(gfx::Size(10, 10));
     root->SetDrawsContent(true);
     root->draw_properties().visible_content_rect = gfx::Rect(0, 0, 10, 10);
     host_impl_->active_tree()->SetRootLayer(root.Pass());
@@ skipping 7827 matching lines @@
   // surface.
   EXPECT_EQ(0, num_lost_surfaces_);
   host_impl_->DidLoseOutputSurface();
   EXPECT_EQ(1, num_lost_surfaces_);
   host_impl_->DidLoseOutputSurface();
   EXPECT_LE(1, num_lost_surfaces_);
 }
 
 }  // namespace
 }  // namespace cc