Reland MSE: Verify MediaLog events created by existing WebM unit tests

media/base/mock_media_log.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_MOCK_MEDIA_LOG_H_
 #define MEDIA_BASE_MOCK_MEDIA_LOG_H_
 
+#include <string>
+
 #include "media/base/media_log.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
+// Helper macros to reduce boilerplate when verifying media log entries.
+// |outer| is the std::string searched for substring |sub|.
+#define CONTAINS_STRING(outer, sub) (std::string::npos != (outer).find(sub))
+
+// "media_log_" is expected to be a scoped_refptr<MockMediaLog>, optionally a
+// StrictMock, in scope of the usage of this macro.
+#define EXPECT_MEDIA_LOG(x) EXPECT_CALL(*media_log_, DoAddEventLogString((x)))
+
 namespace media {
 
 class MockMediaLog : public MediaLog {
  public:
   MockMediaLog();
 
   MOCK_METHOD1(DoAddEventLogString, void(const std::string& event));
 
   // Trampoline method to workaround GMOCK problems with scoped_ptr<>.
   // Also simplifies tests to be able to string match on the log string
   // representation on the added event.
   void AddEvent(scoped_ptr<MediaLogEvent> event) override {
     DoAddEventLogString(MediaEventToLogString(*event));
   }
 
  protected:
   virtual ~MockMediaLog();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockMediaLog);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MOCK_MEDIA_LOG_H_