media: Support MojoRendererService in the browser process.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 97268c669f521bc8dfbc8b46f924cf49db4bc407..29108fb601d9b0ea5f8b21da6fb4398c6f02aa5d 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1504,6 +1504,9 @@
 
     # Experiment: http://crbug.com/426914
     'envoy%': 0,
+    
+    # Experiment to enable mojo based media renderer: http://crbug.com/431776
+    'enable_mojo_media_renderer%': 0,
 
     'conditions': [
       ['buildtype=="Official"', {
@@ -2662,6 +2665,9 @@
       ['enable_browser_cdms==1', {
         'defines': ['ENABLE_BROWSER_CDMS'],
       }],
+      ['enable_mojo_media_renderer==1', {
+        'defines': ['ENABLE_MOJO_MEDIA_RENDERER'],
+      }],
       ['configuration_policy==1', {
         'defines': ['ENABLE_CONFIGURATION_POLICY'],
       }],