media: Simplify {Audio|Video}Decoder initialization callback.

media/base/test_helpers.cc

Index: media/base/test_helpers.cc
diff --git a/media/base/test_helpers.cc b/media/base/test_helpers.cc
index bbfbd64a5a906aa4e162de32cc4e9d765a062826..f4ba9915007b62ce793e9429c5f656b5690c96c8 100644
--- a/media/base/test_helpers.cc
+++ b/media/base/test_helpers.cc
@@ -27,6 +27,7 @@ class MockCallback : public base::RefCountedThreadSafe<MockCallback> {
  public:
   MockCallback();
   MOCK_METHOD0(Run, void());
+  MOCK_METHOD1(RunWithBool, void(bool));
   MOCK_METHOD1(RunWithStatus, void(PipelineStatus));
 
  protected:
@@ -46,6 +47,12 @@ base::Closure NewExpectedClosure() {
   return base::Bind(&MockCallback::Run, callback);
 }
 
+base::Callback<void(bool)> NewExpectedBoolCB(bool success) {
+  StrictMock<MockCallback>* callback = new StrictMock<MockCallback>();
+  EXPECT_CALL(*callback, RunWithBool(success));
+  return base::Bind(&MockCallback::RunWithBool, callback);
+}
+
 PipelineStatusCB NewExpectedStatusCB(PipelineStatus status) {
   StrictMock<MockCallback>* callback = new StrictMock<MockCallback>();
   EXPECT_CALL(*callback, RunWithStatus(status));