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

cc/trees/layer_tree_host_unittest_context.cc

Index: cc/trees/layer_tree_host_unittest_context.cc
diff --git a/cc/trees/layer_tree_host_unittest_context.cc b/cc/trees/layer_tree_host_unittest_context.cc
index dedf9590e969c0f4be6f61babbd4d878dddb8204..e4402601687db6b803fab1d5e91b4ca421369270 100644
--- a/cc/trees/layer_tree_host_unittest_context.cc
+++ b/cc/trees/layer_tree_host_unittest_context.cc
@@ -395,8 +395,8 @@ class MultipleCompositeDoesNotCreateOutputSurface
   }
 
   void BeginTest() override {
-    layer_tree_host()->Composite(base::TimeTicks());
-    layer_tree_host()->Composite(base::TimeTicks());
+    layer_tree_host()->Composite(base::TimeTicks::FromInternalValue(1));
+    layer_tree_host()->Composite(base::TimeTicks::FromInternalValue(2));
   }
 
   scoped_ptr<OutputSurface> CreateOutputSurface() override {
@@ -442,12 +442,12 @@ class FailedCreateDoesNotCreateExtraOutputSurface
 
   void BeginTest() override {
     // First composite tries to create a surface.
-    layer_tree_host()->Composite(base::TimeTicks());
+    layer_tree_host()->Composite(base::TimeTicks::FromInternalValue(1));
     EXPECT_EQ(num_requests_, 2);
     EXPECT_TRUE(has_failed_);
 
     // Second composite should not request or fail.
-    layer_tree_host()->Composite(base::TimeTicks());
+    layer_tree_host()->Composite(base::TimeTicks::FromInternalValue(2));
     EXPECT_EQ(num_requests_, 2);
     EndTest();
   }
@@ -493,7 +493,9 @@ class LayerTreeHostContextTestCommitAfterDelayedOutputSurface
         LayerTreeHostContextTest::CreateOutputSurface());
   }
 
-  void BeginTest() override { layer_tree_host()->Composite(base::TimeTicks()); }
+  void BeginTest() override {
+    layer_tree_host()->Composite(base::TimeTicks::FromInternalValue(1));
+  }
 
   void ScheduleComposite() override {
     if (creating_output_)
@@ -527,7 +529,7 @@ class LayerTreeHostContextTestAvoidUnnecessaryComposite
 
   void BeginTest() override {
     in_composite_ = true;
-    layer_tree_host()->Composite(base::TimeTicks());
+    layer_tree_host()->Composite(base::TimeTicks::FromInternalValue(1));
     in_composite_ = false;
   }