Fix crash in extension_popup_controller.mm appearing when devtools is closed

chrome/browser/ui/cocoa/extensions/extension_popup_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/extensions/extension_popup_controller.h"
 
 #include <algorithm>
 
 #include "chrome/browser/devtools/devtools_window.h"
 #include "chrome/browser/extensions/extension_host.h"
@@ skipping 63 matching lines @@
     [controller_ onViewDidShow];
   }
 
  private:
   ExtensionPopupController* controller_; // Weak; owns this.
 };
 
 class DevtoolsNotificationBridge : public content::NotificationObserver {
  public:
   explicit DevtoolsNotificationBridge(ExtensionPopupController* controller)
-    : controller_(controller) {}
+    : controller_(controller),
+      render_view_host_([controller_ extensionHost]->render_view_host()) {}
 
   virtual void Observe(
       int type,
       const content::NotificationSource& source,
       const content::NotificationDetails& details) OVERRIDE {
     switch (type) {
       case chrome::NOTIFICATION_EXTENSION_HOST_DID_STOP_LOADING: {
         if (content::Details<extensions::ExtensionHost>(
                 [controller_ extensionHost]) == details) {
           [controller_ showDevTools];
         }
         break;
       }
       case content::NOTIFICATION_DEVTOOLS_AGENT_ATTACHED: {
-        RenderViewHost* rvh = [controller_ extensionHost]->render_view_host();
-        if (content::Details<RenderViewHost>(rvh) == details)
+        if (content::Details<RenderViewHost>(render_view_host_) == details)
           // Set the flag on the controller so the popup is not hidden when
           // the dev tools get focus.
           [controller_ setBeingInspected:YES];
         break;
       }
       case content::NOTIFICATION_DEVTOOLS_AGENT_DETACHED: {
-        RenderViewHost* rvh = [controller_ extensionHost]->render_view_host();
-        if (content::Details<RenderViewHost>(rvh) == details)
+        if (content::Details<RenderViewHost>(render_view_host_) == details)
           // Allow the devtools to finish detaching before we close the popup
           [controller_ performSelector:@selector(close)
                             withObject:nil
                             afterDelay:0.0];
         break;
       }
       default: {
         NOTREACHED() << "Received unexpected notification";
         break;
       }
     };
   }
 
  private:
   ExtensionPopupController* controller_;
+  // RenderViewHost for controller. Hold onto this separately because we need to
+  // know what it is for notifications, but our ExtensionHost may not be valid.
+  RenderViewHost* render_view_host_;
 };
 
 @implementation ExtensionPopupController
 
 - (id)initWithHost:(extensions::ExtensionHost*)host
       parentWindow:(NSWindow*)parentWindow
         anchoredAt:(NSPoint)anchoredAt
      arrowLocation:(info_bubble::BubbleArrowLocation)arrowLocation
            devMode:(BOOL)devMode {
   scoped_nsobject<InfoBubbleWindow> window(
@@ skipping 58 matching lines @@
   [super dealloc];
 }
 
 - (void)showDevTools {
   DevToolsWindow::OpenDevToolsWindow(host_->render_view_host());
 }
 
 - (void)windowWillClose:(NSNotification *)notification {
   [super windowWillClose:notification];
   gPopup = nil;
-  if (host_->view()) {
+  if (host_->view())
     host_->view()->set_container(NULL);
-    host_.reset();
-  }
+  host_.reset();
 }
 
 - (void)windowDidResignKey:(NSNotification*)notification {
   if (!beingInspected_)
     [super windowDidResignKey:notification];
 }
 
 - (BOOL)isClosing {
   return [static_cast<InfoBubbleWindow*>([self window]) isClosing];
 }
@@ skipping 158 matching lines @@
   return minSize;
 }
 
 // Private (TestingAPI)
 + (NSSize)maxPopupSize {
   NSSize maxSize = {ExtensionViewMac::kMaxWidth, ExtensionViewMac::kMaxHeight};
   return maxSize;
 }
 
 @end