MacViews: Fix failing mouse capture unittests.

ui/views/cocoa/bridged_native_widget.mm

 // 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.
 
 #import "ui/views/cocoa/bridged_native_widget.h"
 
 #import <objc/runtime.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1010 matching lines @@
 // BridgedNativeWidget, CocoaMouseCaptureDelegate:
 
 void BridgedNativeWidget::PostCapturedEvent(NSEvent* event) {
   [bridged_view_ processCapturedMouseEvent:event];
 }
 
 void BridgedNativeWidget::OnMouseCaptureLost() {
   native_widget_mac_->GetWidget()->OnMouseCaptureLost();
 }
 
+NSWindow* BridgedNativeWidget::GetWindow() const {
+  return window_;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BridgedNativeWidget, FocusChangeListener:
 
 void BridgedNativeWidget::OnWillChangeFocus(View* focused_before,
                                             View* focused_now) {
 }
 
 void BridgedNativeWidget::OnDidChangeFocus(View* focused_before,
                                            View* focused_now) {
   ui::InputMethod* input_method =
@@ skipping 312 matching lines @@
   [bridged_view_ setMouseDownCanMoveWindow:draggable];
   // AppKit will not update its cache of mouseDownCanMoveWindow unless something
   // changes. Previously we tried adding an NSView and removing it, but for some
   // reason it required reposting the mouse-down event, and didn't always work.
   // Calling the below seems to be an effective solution.
   [window_ setMovableByWindowBackground:NO];
   [window_ setMovableByWindowBackground:YES];
 }
 
 }  // namespace views