browser: implement multiple permission requesting

content/public/browser/permission_manager.h

Index: content/public/browser/permission_manager.h
diff --git a/content/public/browser/permission_manager.h b/content/public/browser/permission_manager.h
index 84571ed4d41829cd010081ff0ac0673c1d6e972d..32c8f7fa5109a6c9133a2b95ef2080eac5317fdc 100644
--- a/content/public/browser/permission_manager.h
+++ b/content/public/browser/permission_manager.h
@@ -40,12 +40,28 @@ class CONTENT_EXPORT PermissionManager {
       bool user_gesture,
       const base::Callback<void(PermissionStatus)>& callback) = 0;
 
-  // Cancels a previously requested permission. The given parameter must match
-  // the ones passed to the RequestPermission call.
-  virtual void CancelPermissionRequest(PermissionType permission,
-                                       RenderFrameHost* render_frame_host,
-                                       int request_id,
-                                       const GURL& requesting_origin) = 0;
+  // Requests multiple permissions on behalf of a frame identified by
+  // render_frame_host.
+  // When the permission request is handled, whether it failed, timed out or
+  // succeeded, the |callback| will be run. The order of statuses in the
+  // returned vector will correspond to the order of requested permission
+  // types.
+  // Returns a request id which can be used to cancel the request (see
+  // CancelPermissionRequest). This can be kNoPendingOperation if
+  // there is no further need to cancel the permission in which case |callback|
+  // was invoked.
+  virtual int RequestPermissions(
+      const std::vector<PermissionType>& permission,
+      RenderFrameHost* render_frame_host,
+      const GURL& requesting_origin,
+      bool user_gesture,
+      const base::Callback<void(
+          const std::vector<PermissionStatus>&)>& callback) = 0;
+
+  // Cancels a previous permission request specified by |request_id|. Cancelling
+  // an already cancelled request or providing the |request_id|
+  // kNoPendingOperation is a no-op.
+  virtual void CancelPermissionRequest(int request_id) = 0;
 
   // Returns the permission status of a given requesting_origin/embedding_origin
   // tuple. This is not taking a RenderFrameHost because the call might happen