Fixed crash when chrome.runtime.reload() is called with app windows open

chrome/browser/extensions/extension_process_manager.h

Index: chrome/browser/extensions/extension_process_manager.h
diff --git a/chrome/browser/extensions/extension_process_manager.h b/chrome/browser/extensions/extension_process_manager.h
index b234b3c0e5e06082f793db08998ad90a503aea06..64d4d261434877d312b2753062b42ba1b30989c4 100644
--- a/chrome/browser/extensions/extension_process_manager.h
+++ b/chrome/browser/extensions/extension_process_manager.h
@@ -199,6 +199,10 @@ class ExtensionProcessManager : public content::NotificationObserver {
   // extension. Does nothing if this is not an extension renderer.
   void RegisterRenderViewHost(content::RenderViewHost* render_view_host);
 
+  // Unregister RenderViewHosts and clear background page data for an extension
+  // which has been unloaded.
+  void UnregisterExtension(const std::string& extension_id);
+
   // Clears background page data for this extension.
   void ClearBackgroundPageData(const std::string& extension_id);