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 24ffcd46e4e3a933a2089b59773c81211692600f..b28e3737c6eb74fc1287028f0f94f136640aad0f 100644
--- a/cc/trees/layer_tree_host_unittest_context.cc
+++ b/cc/trees/layer_tree_host_unittest_context.cc
@@ -393,8 +393,8 @@ 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 {
@@ -430,8 +430,8 @@ class FailedCreateDoesNotCreateExtraOutputSurface
   }
 
   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));
   }
 
   void DidInitializeOutputSurface() override { EXPECT_TRUE(false); }
@@ -473,7 +473,9 @@ 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_)
@@ -506,7 +508,7 @@ 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;
   }