Stop sending events and messages to content script contexts after their

chrome/renderer/extensions/chrome_v8_context_set.cc

 // Copyright (c) 2012 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/renderer/extensions/chrome_v8_context_set.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/tracked_objects.h"
 #include "base/values.h"
@@ skipping 62 matching lines @@
   contexts_.insert(context);
 }
 
 void ChromeV8ContextSet::Remove(ChromeV8Context* context) {
   if (contexts_.erase(context)) {
     context->clear_web_frame();
     MessageLoop::current()->DeleteSoon(FROM_HERE, context);
   }
 }
 
-ChromeV8ContextSet::ContextSet ChromeV8ContextSet::GetAll()
-    const {
+ChromeV8ContextSet::ContextSet ChromeV8ContextSet::GetAll() const {
   return contexts_;
 }
 
 ChromeV8Context* ChromeV8ContextSet::GetCurrent() const {
   if (!v8::Context::InContext())
     return NULL;
   else
     return GetByV8Context(v8::Context::GetCurrent());
 }
 
@@ skipping 49 matching lines @@
       CHECK(arguments.Get(i, &item));
       v8_arguments.push_back(converter->ToV8Value(item, context));
     }
 
     v8::Handle<v8::Value> retval;
     (*it)->CallChromeHiddenMethod(
         method_name, v8_arguments.size(), &v8_arguments[0], &retval);
   }
 }
 
+void ChromeV8ContextSet::OnExtensionUnloaded(const std::string& extension_id) {
+  ContextSet contexts = GetAll();
+
+  // Clean up contexts belonging to the unloaded extension. This is done so
+  // that content scripts (which remain injected into the page) don't continue
+  // receiving events and sending messages.
+  for (ContextSet::iterator it = contexts.begin(); it != contexts.end();
+       ++it) {
+    if ((*it)->extension() && (*it)->extension()->id() == extension_id) {
+      (*it)->DispatchOnUnloadEvent();
+      Remove(*it);
+    }
+  }
+}
+
 }  // namespace extensions