[MacViews] Enable dragging a window by its caption/draggable areas.

ui/base/test/windowed_nsnotification_observer.mm

Index: ui/base/test/windowed_nsnotification_observer.mm
diff --git a/ui/base/test/windowed_nsnotification_observer.mm b/ui/base/test/windowed_nsnotification_observer.mm
new file mode 100644
index 0000000000000000000000000000000000000000..67818c605771e7b7cf7c2f51d2bded332993afaf
--- /dev/null
+++ b/ui/base/test/windowed_nsnotification_observer.mm
@@ -0,0 +1,63 @@
+// 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.
+
+#import "ui/base/test/windowed_nsnotification_observer.h"
+
+#import "base/mac/sdk_forward_declarations.h"
+
+@interface WindowedNSNotificationObserver ()
+- (void)observe:(NSNotification*)notification;
+@end
+
+@implementation WindowedNSNotificationObserver
+
+- (id)initForNotification:(NSString*)name {
+  if (self = [super init]) {
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(observe:)
+                                                 name:name
+                                               object:nil];
+  }
+  return self;
+}
+
+- (id)initForNotification:(NSString*)name
+              andBundleId:(NSString*)bundleId {
+  if (self = [super init]) {
+    bundleId_.reset([[bundleId copy] retain]);
+    [[[NSWorkspace sharedWorkspace] notificationCenter]
+        addObserver:self
+           selector:@selector(observe:)
+               name:name
+             object:nil];
+  }
+  return self;
+}
+
+- (void)observe:(NSNotification*)notification {
+  if (bundleId_) {
+    NSRunningApplication* application =
+        [[notification userInfo] objectForKey:NSWorkspaceApplicationKey];
+    if (![[application bundleIdentifier] isEqualToString:bundleId_])
+      return;
+
+    [[[NSWorkspace sharedWorkspace] notificationCenter] removeObserver:self];
+  } else {
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+  }
+
+  notificationReceived_ = YES;
+  if (runLoop_.get())
+    runLoop_->Quit();
+}
+
+- (void)wait {
+  if (notificationReceived_)
+    return;
+
+  runLoop_.reset(new base::RunLoop);
+  runLoop_->Run();
+}
+
+@end