mash: Use the new mus drag and drop API to get drag working in mash.

services/ui/public/cpp/window_tree_client.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/public/cpp/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 623 matching lines @@
 }
 
 void WindowTreeClient::StopPointerWatcher() {
   DCHECK(has_pointer_watcher_);
   tree_->StopPointerWatcher();
   has_pointer_watcher_ = false;
 }
 
 void WindowTreeClient::PerformDragDrop(
     Window* window,
-    int drag_pointer,
     const std::map<std::string, std::vector<uint8_t>>& drag_data,
     int drag_operation,
     const gfx::Point& cursor_location,
     const SkBitmap& bitmap,
     const base::Callback<void(bool, uint32_t)>& callback) {
   DCHECK(!current_drag_state_);
 
   // TODO(erg): Pass |cursor_location| and |bitmap| in PerformDragDrop() when
   // we start showing an image representation of the drag under he cursor.
 
   if (window->drop_target()) {
     // To minimize the number of round trips, copy the drag drop data to our
     // handler here, instead of forcing mus to send this same data back.
     OnDragDropStart(
         mojo::Map<mojo::String, mojo::Array<uint8_t>>::From(drag_data));
   }
 
   uint32_t current_drag_change = ScheduleInFlightChange(
       base::MakeUnique<InFlightDragChange>(window, ChangeType::DRAG_LOOP));
   current_drag_state_.reset(new CurrentDragState{
       current_drag_change, ui::mojom::kDropEffectNone, callback});
 
   tree_->PerformDragDrop(
-      current_drag_change, window->server_id(), drag_pointer,
+      current_drag_change, window->server_id(),
       mojo::Map<mojo::String, mojo::Array<uint8_t>>::From(drag_data),
       drag_operation);
 }
 
 void WindowTreeClient::CancelDragDrop(Window* window) {
   // Server will clean up drag and fail the in-flight change.
   tree_->CancelDragDrop(window->server_id());
 }
 
 void WindowTreeClient::PerformWindowMove(
@@ skipping 728 matching lines @@
     Window* window,
     const gfx::Vector2d& offset,
     const gfx::Insets& hit_area) {
   if (window_manager_internal_client_) {
     window_manager_internal_client_->SetUnderlaySurfaceOffsetAndExtendedHitArea(
         server_id(window), offset.x(), offset.y(), hit_area);
   }
 }
 
 }  // namespace ui