Log MediaSource parsing errors to the MediaLog so they can appear in chrome:media-internals.

media/webm/webm_content_encodings_client_unittest.cc

Index: media/webm/webm_content_encodings_client_unittest.cc
diff --git a/media/webm/webm_content_encodings_client_unittest.cc b/media/webm/webm_content_encodings_client_unittest.cc
index bf45bd7b1b4791abfd479633c3bc699a0f7112fe..bb9e6943126eddd6e41ebe3e0a6484fe48adf726 100644
--- a/media/webm/webm_content_encodings_client_unittest.cc
+++ b/media/webm/webm_content_encodings_client_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/bind.h"
 #include "media/webm/webm_constants.h"
 #include "media/webm/webm_content_encodings_client.h"
 #include "media/webm/webm_parser.h"
@@ -12,7 +13,8 @@ namespace media {
 class WebMContentEncodingsClientTest : public testing::Test {
  public:
   WebMContentEncodingsClientTest()
-      : parser_(kWebMIdContentEncodings, &client_) {}
+      : client_(LogCB()),
+        parser_(kWebMIdContentEncodings, &client_) {}
 
   void ParseAndExpectToFail(const uint8* buf, int size) {
     int result = parser_.Parse(buf, size);