Break out EventDispatchingWindow into separate class

brightray/browser/mac/event_dispatching_window.mm

@@ -0,0 +1,34 @@
+// Copyright (c) 2016 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "browser/mac/event_dispatching_window.h"
+
+@implementation EventDispatchingWindow
+
+- (void)sendEvent:(NSEvent*)event {
+  if (!redispatchingEvent_)
+    [super sendEvent:event];
+}
+
+- (BOOL)performKeyEquivalent:(NSEvent*)event {
+  if (redispatchingEvent_)
+    return NO;
+  else
+    return [super performKeyEquivalent:event];
+ }
+
+- (void)redispatchKeyEvent:(NSEvent*)event {
+  NSEventType eventType = [event type];
+  if (eventType != NSKeyDown && eventType != NSKeyUp &&
+      eventType != NSFlagsChanged) {
+    return;
+  }
+
+  // Redispatch the event.
+  redispatchingEvent_ = YES;
+  [NSApp sendEvent:event];
+  redispatchingEvent_ = NO;
+}
+
+@end