Remove gfx::FrameTime for a single clock source

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index dad00450e7ba27fad94da6b50f13f8c3be1a17d9..f170154e48960f35f35f6ca2b8683fc61a1c4b38 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -34,7 +34,7 @@
 #include "cc/trees/single_thread_proxy.h"
 #include "cc/trees/thread_proxy.h"
 #include "testing/gmock/include/gmock/gmock.h"
-#include "ui/gfx/frame_time.h"
+
 #include "ui/gfx/geometry/size_conversions.h"
 
 namespace cc {
@@ -786,7 +786,7 @@ void LayerTreeTest::DispatchSetNextCommitForcesRedraw() {
 void LayerTreeTest::DispatchCompositeImmediately() {
   DCHECK(!proxy() || proxy()->IsMainThread());
   if (layer_tree_host_)
-    layer_tree_host_->Composite(gfx::FrameTime::Now());
+    layer_tree_host_->Composite(base::TimeTicks::Now());
 }
 
 void LayerTreeTest::RunTest(bool threaded,