media: Plumb MediaLog to MojoVideoDecoderService.

media/base/media_log.h

Index: media/base/media_log.h
diff --git a/media/base/media_log.h b/media/base/media_log.h
index d138fd6b17133534bb16dc959a468ffca94b164e..08eadc587f2ca69499e0633e65aae1e358730a30 100644
--- a/media/base/media_log.h
+++ b/media/base/media_log.h
@@ -101,6 +101,10 @@ class MEDIA_EXPORT MediaLog {
   void SetDoubleProperty(const std::string& key, double value);
   void SetBooleanProperty(const std::string& key, bool value);
 
+  // Getter for |id_|. Used by MojoMediaLogService to construct MediaLogEvents
+  // to log into this MediaLog.
+  int32_t id() const { return id_; }
+
  private:
   // A unique (to this process) id for this MediaLog.
   int32_t id_;