Cleanup everything but net/ for our first clang plugins.

chrome/browser/tab_contents/tab_contents_observer.cc

Index: chrome/browser/tab_contents/tab_contents_observer.cc
diff --git a/chrome/browser/tab_contents/tab_contents_observer.cc b/chrome/browser/tab_contents/tab_contents_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5ad1e1d79ac2ae63e6bd6668964f0413031108ba
--- /dev/null
+++ b/chrome/browser/tab_contents/tab_contents_observer.cc
@@ -0,0 +1,9 @@
+// Copyright (c) 2011 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.
+
+#include "chrome/browser/tab_contents/tab_contents_observer.h"
+
+bool TabContentsObserver::OnMessageReceived(const IPC::Message& message) {
+  return false;
+}