Add a command line flag for dumping trace events to VLOG

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 e880510bacead566473b02475296be94b3f9f9a0..89ef4be16c32039ebc0869bb7e020b1fd76d2dfb 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -9,6 +9,7 @@
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/timing_function.h"
+#include "cc/base/switches.h"
 #include "cc/base/thread_impl.h"
 #include "cc/input/input_handler.h"
 #include "cc/layers/content_layer.h"
@@ -313,7 +314,7 @@ LayerTreeTest::LayerTreeTest()
   // Tests should timeout quickly unless --cc-layer-tree-test-no-timeout was
   // specified (for running in a debugger).
   CommandLine* command_line = CommandLine::ForCurrentProcess();
-  if (!command_line->HasSwitch("cc-layer-tree-test-no-timeout"))
+  if (!command_line->HasSwitch(switches::kCCLayerTreeTestNoTimeout))
     timeout_seconds_ = 5;
 }
 
@@ -545,7 +546,7 @@ void LayerTreeTest::DispatchComposite() {
 
 void LayerTreeTest::RunTest(bool threaded) {
   if (threaded) {
-    impl_thread_.reset(new base::Thread("LayerTreeTest"));
+    impl_thread_.reset(new base::Thread("Compositor"));
     ASSERT_TRUE(impl_thread_->Start());
   }