Break extensions ProcessManager dependency on Runtime API

extensions/browser/process_manager_observer.h

Index: extensions/browser/process_manager_observer.h
diff --git a/extensions/browser/process_manager_observer.h b/extensions/browser/process_manager_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..93dc3a1c2d71c61e2e8e876da5ae643fde1eec91
--- /dev/null
+++ b/extensions/browser/process_manager_observer.h
@@ -0,0 +1,21 @@
+// 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 EXTENSIONS_BROWSER_PROCESS_MANAGER_OBSERVER_H_
+#define EXTENSIONS_BROWSER_PROCESS_MANAGER_OBSERVER_H_
+
+namespace extensions {
+class Extension;
+
+class ProcessManagerObserver {
+ public:
+  virtual ~ProcessManagerObserver() {}
+
+  // Called immediately after an extension background host is started.
+  virtual void OnBackgroundHostStartup(const Extension* extension) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_PROCESS_MANAGER_OBSERVER_H_