media: Remove SetCdmReadyCB and CdmReadyCB (part 1).

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 4b2128296b178048f76cbf7ee6c34bf0553de40b..b88450457c2f20825fc5c1cd087783e44bd6727f 100644
--- a/media/base/test_helpers.cc
+++ b/media/base/test_helpers.cc
@@ -262,21 +262,4 @@ bool VerifyFakeVideoBufferForTest(
           height == config.coded_size().height());
 }
 
-CallbackPairChecker::CallbackPairChecker() : expecting_b_(false) {
-}
-
-CallbackPairChecker::~CallbackPairChecker() {
-  EXPECT_FALSE(expecting_b_);
-}
-
-void CallbackPairChecker::RecordACalled() {
-  EXPECT_FALSE(expecting_b_);
-  expecting_b_ = true;
-}
-
-void CallbackPairChecker::RecordBCalled() {
-  EXPECT_TRUE(expecting_b_);
-  expecting_b_ = false;
-}
-
 }  // namespace media