Re-add sourceSetTimestampOffset to webmediaplayer_impl

sourceSetTimestampOffset() was removed in r150129 because it looked like it wasn't being used.  It just hadn't been hooked up to WebKit yet.  This patch will add it back.

BUG=141659

Review URL: https://chromiumcodereview.appspot.com/10823260

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150894 0039d316-1c4b-4281-b951-d872f2087c98

webkit/media/webmediaplayer_impl.cc

@@ -682,6 +682,11 @@ void WebMediaPlayerImpl::sourceEndOfStream(
     GetClient()->durationChanged();
 }
 
+bool WebMediaPlayerImpl::sourceSetTimestampOffset(const WebKit::WebString& id,
+                                                  double offset) {
+  return proxy_->DemuxerSetTimestampOffset(id.utf8().data(), offset);
+}
+
 WebKit::WebMediaPlayer::MediaKeyException
 WebMediaPlayerImpl::generateKeyRequest(const WebString& key_system,
                                        const unsigned char* init_data,

webkit/media/webmediaplayer_impl.h

@@ -199,6 +199,8 @@ class WebMediaPlayerImpl
                             unsigned length);
   virtual bool sourceAbort(const WebKit::WebString& id);
   virtual void sourceEndOfStream(EndOfStreamStatus status);
+  virtual bool sourceSetTimestampOffset(const WebKit::WebString& id,
+                                        double offset);
 
   virtual MediaKeyException generateKeyRequest(
       const WebKit::WebString& key_system,