fix sign-compare warning.

content/common/gpu/media/video_encode_accelerator_unittest.cc

Index: content/common/gpu/media/video_encode_accelerator_unittest.cc
diff --git a/content/common/gpu/media/video_encode_accelerator_unittest.cc b/content/common/gpu/media/video_encode_accelerator_unittest.cc
index b50e902bc5744d635e233ee7b445f166883e9e5b..21f671a6d4ca2540181e8a9f7d4a20cff33324ea 100644
--- a/content/common/gpu/media/video_encode_accelerator_unittest.cc
+++ b/content/common/gpu/media/video_encode_accelerator_unittest.cc
@@ -533,7 +533,7 @@ VEAClient::VEAClient(const TestStream& test_stream,
 
   // Calculate the number of frames in the input stream by dividing its length
   // in bytes by frame size in bytes.
-  CHECK_EQ(test_stream_.input_file.length() % input_buffer_size_, 0)
+  CHECK_EQ(test_stream_.input_file.length() % input_buffer_size_, 0U)
       << "Stream byte size is not a product of calculated frame byte size";
   num_frames_in_stream_ = test_stream_.input_file.length() / input_buffer_size_;
   CHECK_GT(num_frames_in_stream_, 0UL);