cc: Allow command line flag to prevent unit test timeouts.

cc/test/layer_tree_test.h

Index: cc/test/layer_tree_test.h
diff --git a/cc/test/layer_tree_test.h b/cc/test/layer_tree_test.h
index 8302874f8062c97b9deb2f663328bc978bd74145..7f76d739fd76d29bffbad708754b35a43c1df059 100644
--- a/cc/test/layer_tree_test.h
+++ b/cc/test/layer_tree_test.h
@@ -156,6 +156,8 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   bool started_;
   bool ended_;
 
+  int timeout_seconds_;
+
   scoped_ptr<Thread> main_ccthread_;
   scoped_ptr<base::Thread> impl_thread_;
   base::CancelableClosure timeout_;