gfx::Screen: Replace GetWindowUnderCursor() with IsWindowUnderCursor().

blimp/engine/app/ui/blimp_screen.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 "blimp/engine/app/ui/blimp_screen.h"
 
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/display/display_observer.h"
 #include "ui/gfx/geometry/size.h"
@@ skipping 29 matching lines @@
   display_.SetScaleAndBounds(scale, gfx::Rect(size));
 
   FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
                     OnDisplayMetricsChanged(display_, metrics));
 }
 
 gfx::Point BlimpScreen::GetCursorScreenPoint() {
   return gfx::Point();
 }
 
-gfx::NativeWindow BlimpScreen::GetWindowUnderCursor() {
+bool BlimpScreen::IsWindowUnderCursor(gfx::NativeWindow window) {
   NOTIMPLEMENTED();
-  return gfx::NativeWindow(nullptr);
+  return false;
 }
 
 gfx::NativeWindow BlimpScreen::GetWindowAtScreenPoint(const gfx::Point& point) {
   return window_tree_host_
              ? window_tree_host_->window()->GetTopWindowContainingPoint(point)
              : gfx::NativeWindow(nullptr);
 }
 
 int BlimpScreen::GetNumDisplays() const {
   return kNumDisplays;
@@ skipping 25 matching lines @@
 void BlimpScreen::AddObserver(display::DisplayObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void BlimpScreen::RemoveObserver(display::DisplayObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 }  // namespace engine
 }  // namespace blimp