Implement HasPermission() method in PermissionService.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index c44788bdeab2db9697116dce9e805bb2e4a22994..4a55094fde203cb6f98df29136fc8545b6cde0d5 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -452,6 +452,11 @@ class CONTENT_EXPORT ContentBrowserClient {
                                        WebContents* web_contents,
                                        const GURL& frame_url,
                                        const GURL& main_frame_url) {}
+  virtual void HasPermission(
+      PermissionType permission,
+      WebContents* web_contents,
+      const GURL& requesting_frame,
+      const base::Callback<void(bool)>& result_callback);
 
   // Returns true if the given page is allowed to open a window of the given
   // type. If true is returned, |no_javascript_access| will indicate whether