Rewire Android WebView's compositor changed signal.

android_webview/browser/compositor_id.h

+// Copyright 2016 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 ANDROID_WEBVIEW_BROWSER_COMPOSITOR_ID_H_
+#define ANDROID_WEBVIEW_BROWSER_COMPOSITOR_ID_H_
+
+namespace android_webview {
+
+struct CompositorID {
+  CompositorID();
+  CompositorID(int process_id, int routing_id);
+  CompositorID(const CompositorID& other);
+
+  bool operator==(const CompositorID& other) const;

[boliu, 2016/06/10 15:40:33]

for binary operators, I think general preference is for "external" ones, ie
defined not in the class, but as global functions

[hush (inactive), 2016/06/10 23:28:44]

Done.

+  bool operator!=(const CompositorID& other) const;
+  bool operator<(const CompositorID& other) const;
+  bool operator>(const CompositorID& other) const;
+
+  int process_id;
+  int routing_id;
+};
+
+}  // namespace android_webview
+
+#endif  // ANDROID_WEBVIEW_BROWSER_COMPOSITOR_ID_H_