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 e0fe9c069c426a5eaa1f0b8134abc510cb4b5440..ad865574d873458fb3cc9191837b0fbc3dcb1064 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/ordered_simple_task_runner.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
@@ -20,6 +21,13 @@ BeginFrameArgs CreateBeginFrameArgsForTesting(int64 frame_time,
                                               int64 interval);
 BeginFrameArgs CreateExpiredBeginFrameArgsForTesting();
 
+// Creates a BeginFrameArgs using the fake Now value stored on the
+// OrderSimpleTaskRunner.
+BeginFrameArgs CreateBeginFrameArgsForTesting(
+    const OrderedSimpleTaskRunner& task_runner);

[brianderson, 2014/08/20 20:04:31]

Instead of having such a strong dependency on the OrderedSimpleTask runner, it
would be better to just take in a timestamp for Now.

I don't think OrderedSimpleTaskRunner should be exposing a public version of its
concept of Now() anyway.

[mithro-old, 2014/08/21 17:39:18]

I feel like as the system evolved it might want more information to create the
begin frame args which won't be available just on a timestamp. With the refactor
it's now only dependent on the TestNowSource. It is also a strong signal that
you should be using *this* CreateBeginFrameArgsForTesting (which will get the
right Now() value) rather than the other ones.

+BeginFrameArgs CreateExpiredBeginFrameArgsForTesting(
+    const OrderedSimpleTaskRunner& task_runner);
+
 // gtest helpers -- these *must* be in the same namespace as the types they
 // operate on.