Expose text track settings in Content and implement for Android

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 67ee5d52858553fc8608c7bb5691aa1006b2411d..283be24ef7bcbd431ae8bec34dc477a1823255b4 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -39,6 +39,7 @@ struct AccessibilityHostMsg_FindInPageResultParams;
 struct AccessibilityHostMsg_LocationChangeParams;
 struct FrameHostMsg_DidFailProvisionalLoadWithError_Params;
 struct FrameHostMsg_OpenURL_Params;
+struct FrameMsg_TextTrackSettings_Params;
 #if defined(OS_MACOSX) || defined(OS_ANDROID)
 struct FrameHostMsg_ShowPopup_Params;
 #endif
@@ -372,6 +373,9 @@ class CONTENT_EXPORT RenderFrameHostImpl
   void SetAccessibilityCallbackForTesting(
       const base::Callback<void(ui::AXEvent, int)>& callback);
 
+  // Send a message to the render process to change text track style settings.
+  void SetTextTrackSettings(const FrameMsg_TextTrackSettings_Params& params);
+
   // Returns a snapshot of the accessibility tree received from the
   // renderer as of the last time an accessibility notification was
   // received.