Look into full URL spec to see whether it is MP4

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 4c5d7a3e37e4de3e3fa88be809293cc7e867c2ec..3e506ad669fdb1e3335031d48f969829cd89eb9f 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -796,10 +796,10 @@ bool UseWebMediaPlayerImpl(const GURL& url) {
 
   // Don't use WMPI if the container likely contains a codec we can't decode in
   // software and platform decoders are not available.
-  if (base::EndsWith(url.path(), ".mp4",
-                     base::CompareCase::INSENSITIVE_ASCII) &&
-      !media::HasPlatformDecoderSupport()) {
-    return false;
+  if (!media::HasPlatformDecoderSupport()) {
+    // Assume "mp4" means H264.

[piman, 2016/09/16 01:45:00]

nit: please add a link to the bug. This logic is very suspicious at first
glance, the bug explains a bit more - it sounds like this is a temporary fix?

[Tima Vaisburd, 2016/09/16 19:04:22]

Done.

+    if (base::ToLowerASCII(url.spec()).find("mp4") != std::string::npos)
+      return false;
   }
 
   // Indicates if the Android MediaPlayer should be used instead of WMPI.