Disable HW H264 decoder for Win7 & add enable flag

content/renderer/media/rtc_video_decoder_unittest.cc

Index: content/renderer/media/rtc_video_decoder_unittest.cc
diff --git a/content/renderer/media/rtc_video_decoder_unittest.cc b/content/renderer/media/rtc_video_decoder_unittest.cc
index 4b765efdd976368f72c515b5a40b94325f5e2237..50f9fb9eddae9e3502a0c4f3f3c3dad44837f366 100644
--- a/content/renderer/media/rtc_video_decoder_unittest.cc
+++ b/content/renderer/media/rtc_video_decoder_unittest.cc
@@ -17,6 +17,11 @@
 #include "media/video/mock_video_decode_accelerator.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_WIN)
+#include "base/command_line.h"
+#include "content/public/common/content_switches.h"
+#endif  // defined(OS_WIN)
+
 using ::testing::_;
 using ::testing::Invoke;
 using ::testing::Return;
@@ -74,6 +79,11 @@ class RTCVideoDecoderTest
         .Times(1)
         .WillRepeatedly(Return(true));
     EXPECT_CALL(*mock_vda_, Destroy()).Times(1);
+
+#if defined(OS_WIN)
+    base::CommandLine::ForCurrentProcess()->AppendSwitch(
+        switches::kEnableWin7HWH264Decoding);
+#endif  // defined(OS_WIN)
   }
 
   void TearDown() override {