Fixing and enhancing OrderedSimpleTaskRunner to allow 100% deterministic tests.

cc/test/begin_frame_args_test.h

Index: cc/test/begin_frame_args_test.h
diff --git a/cc/test/begin_frame_args_test.h b/cc/test/begin_frame_args_test.h
index 0ab1daf21778ac5819ad802cccd0f669fffcda7e..1c75c3775f5845b6ed2c0eae1bb8f0bd6bcb819b 100644
--- a/cc/test/begin_frame_args_test.h
+++ b/cc/test/begin_frame_args_test.h
@@ -9,6 +9,7 @@
 
 #include "base/time/time.h"
 #include "cc/output/begin_frame_args.h"
+#include "cc/test/test_now_source.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
@@ -21,6 +22,13 @@ BeginFrameArgs CreateBeginFrameArgsForTesting(int64 frame_time,
                                               int64 interval);
 BeginFrameArgs CreateExpiredBeginFrameArgsForTesting();
 
+// Creates a BeginFrameArgs using the fake Now value stored on the
+// OrderSimpleTaskRunner.
+BeginFrameArgs CreateBeginFrameArgsForTesting(
+    scoped_refptr<TestNowSource> now_src);
+BeginFrameArgs CreateExpiredBeginFrameArgsForTesting(
+    scoped_refptr<TestNowSource> now_src);
+
 // gtest helpers -- these *must* be in the same namespace as the types they
 // operate on.