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 55ac893bb66950ad2b11de6fc61e6008d262686c..a7f6607aead04d762ca78fb23b4505d36aa0cd81 100644
--- a/content/public/browser/permission_manager.h
+++ b/content/public/browser/permission_manager.h
@@ -36,6 +36,24 @@ class CONTENT_EXPORT PermissionManager {
       bool user_gesture,
       const base::Callback<void(PermissionStatus)>& callback) = 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 kNoPendingRequestOrSubscription 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;

[michaelbai, 2015/09/23 17:51:52]

Are you going to combine RequestPermission into RequestPermissions? they are
same if vector<> only has one permission.

[Lalit Maganti, 2015/09/23 17:57:25]

Yes you're right but no we are not going to do this. We did consider it but we
decided against forcing implementations from supporting a multiple permission
request if they did not want to.

Mounir: anything to add from your end here? 

+
   // Cancels a previous permission request specified by |request_id|. Cancelling
   // an already cancelled request or providing the |request_id|
   // kNoPendingRequestOrSubscription is a no-op.