Revert of mus: Fix event transformation in client code.

ui/views/mus/window_tree_host_mus.cc

 // Copyright 2015 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 "ui/views/mus/window_tree_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/events/event.h"
 #include "ui/views/mus/input_method_mus.h"
 #include "ui/views/mus/native_widget_mus.h"
 #include "ui/views/mus/platform_window_mus.h"
 
 namespace views {
 
 ////////////////////////////////////////////////////////////////////////////////
 // WindowTreeHostMus, public:
 
 WindowTreeHostMus::WindowTreeHostMus(shell::Connector* connector,
                                      NativeWidgetMus* native_widget,
                                      mus::Window* window)
     : native_widget_(native_widget),
       show_state_(ui::PLATFORM_WINDOW_STATE_UNKNOWN) {
   SetPlatformWindow(
       base::WrapUnique(new PlatformWindowMus(this, connector, window)));
+  // The location of events is already transformed, and there is no way to
+  // correctly determine the reverse transform. So, don't attempt to transform
+  // event locations, else the root location is wrong.
+  // TODO(sky): we need to transform for device scale though.
+  dispatcher()->set_transform_events(false);
   compositor()->SetHostHasTransparentBackground(true);
 
   input_method_.reset(new InputMethodMUS(this, window));
   SetSharedInputMethod(input_method_.get());
 }
 
 WindowTreeHostMus::~WindowTreeHostMus() {
   DestroyCompositor();
   DestroyDispatcher();
 }
@@ skipping 29 matching lines @@
   if (native_widget_)
     native_widget_->OnActivationChanged(active);
   WindowTreeHostPlatform::OnActivationChanged(active);
 }
 
 void WindowTreeHostMus::OnCloseRequest() {
   OnHostCloseRequested();
 }
 
 }  // namespace views