Possible fix for ExtensionFunctionDispatcher::DispatchWithCallbackInternal.

extensions/browser/extension_function_dispatcher.cc

 // 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.
 
 #include "extensions/browser/extension_function_dispatcher.h"
 
 #include "base/bind.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 360 matching lines @@
   if (!CheckPermissions(function.get(), params, callback))
     return;
 
   if (!extension) {
     // Skip all of the UMA, quota, event page, activity logging stuff if there
     // isn't an extension, e.g. if the function call was from WebUI.
     function->Run()->Execute();
     return;
   }
 
+  // Fetch the ProcessManager before |this| is possibly invalidated.
+  ProcessManager* process_manager = ProcessManager::Get(browser_context_);
+
   ExtensionSystem* extension_system = ExtensionSystem::Get(browser_context_);
   QuotaService* quota = extension_system->quota_service();
   std::string violation_error = quota->Assess(extension->id(),
                                               function.get(),
                                               &params.arguments,
                                               base::TimeTicks::Now());
 
   if (violation_error.empty()) {
     scoped_ptr<base::ListValue> args(params.arguments.DeepCopy());
 
@@ skipping 12 matching lines @@
   // if function->Run() ended up closing the tab that owns us.
 
   // Check if extension was uninstalled by management.uninstall.
   if (!registry->enabled_extensions().GetByID(params.extension_id))
     return;
 
   // We only adjust the keepalive count for UIThreadExtensionFunction for
   // now, largely for simplicity's sake. This is OK because currently, only
   // the webRequest API uses IOThreadExtensionFunction, and that API is not
   // compatible with lazy background pages.
-  ProcessManager::Get(browser_context_)->IncrementLazyKeepaliveCount(extension);
+  process_manager->IncrementLazyKeepaliveCount(extension);
 }
 
 void ExtensionFunctionDispatcher::OnExtensionFunctionCompleted(
     const Extension* extension) {
   if (extension) {
     ProcessManager::Get(browser_context_)
         ->DecrementLazyKeepaliveCount(extension);
   }
 }
 
@@ skipping 44 matching lines @@
 
 // static
 void ExtensionFunctionDispatcher::SendAccessDenied(
     const ExtensionFunction::ResponseCallback& callback) {
   base::ListValue empty_list;
   callback.Run(ExtensionFunction::FAILED, empty_list,
                "Access to extension API denied.");
 }
 
 }  // namespace extensions