Convert MIDI permission requests to use WebContents in preparation for switching the code to using …

chrome/browser/chrome_content_browser_client.h

Index: chrome/browser/chrome_content_browser_client.h
diff --git a/chrome/browser/chrome_content_browser_client.h b/chrome/browser/chrome_content_browser_client.h
index b1a073b05db132856ca312b3e28f7c215d3a83cb..29d8ed62be6b7e8be76bcada12e2cc7462736178 100644
--- a/chrome/browser/chrome_content_browser_client.h
+++ b/chrome/browser/chrome_content_browser_client.h
@@ -216,6 +216,13 @@ class ChromeContentBrowserClient : public content::ContentBrowserClient {
       bool user_gesture,
       base::Callback<void(bool)> result_callback,
       base::Closure* cancel_callback) OVERRIDE;
+  virtual void RequestMidiSysExPermission(
+      content::WebContents* web_contents,
+      int bridge_id,
+      const GURL& requesting_frame,
+      bool user_gesture,
+      base::Callback<void(bool)> result_callback,
+      base::Closure* cancel_callback) OVERRIDE;
   virtual bool CanCreateWindow(const GURL& opener_url,
                                const GURL& opener_top_level_frame_url,
                                const GURL& source_origin,