MacViews: Implement capture using NSEvent local+global monitors

ui/views/cocoa/cocoa_mouse_capture_delegate.h

+// 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.
+
+#ifndef UI_VIEWS_COCOA_COCOA_MOUSE_CAPTURE_DELEGATE_H_
+#define UI_VIEWS_COCOA_COCOA_MOUSE_CAPTURE_DELEGATE_H_
+
+@class NSEvent;
+
+namespace views {
+
+// Delegate for receiving captured events from a CocoaMouseCapture.
+class CocoaMouseCaptureDelegate {
+ public:
+  // Called when an event has been captured. This may be an event local to the
+  // application, or a global event (sent to another application). If it is a
+  // local event, regular event handling will be suppressed.
+  virtual void PostCapturedEvent(NSEvent* event) = 0;
+
+  // Called once. When another window acquires capture, or when the
+  // CocoaMouseCapture is destroyed.
+  virtual void OnMouseCaptureLost() = 0;
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_COCOA_COCOA_MOUSE_CAPTURE_DELEGATE_H_