Fix event page process cleanup when running in --isolate-extensions mode.

extensions/browser/process_manager.cc

 // Copyright 2013 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/process_manager.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 279 matching lines @@
   FOR_EACH_OBSERVER(ProcessManagerObserver,
                     observer_list_,
                     OnExtensionFrameRegistered(extension->id(),
                                                render_frame_host));
 }
 
 void ProcessManager::UnregisterRenderFrameHost(
     content::RenderFrameHost* render_frame_host) {
   ExtensionRenderFrames::iterator frame =
       all_extension_frames_.find(render_frame_host);
-
   if (frame != all_extension_frames_.end()) {
     std::string extension_id = GetExtensionID(render_frame_host);
     // Keepalive count, balanced in RegisterRenderFrame.
     ReleaseLazyKeepaliveCountForFrame(render_frame_host);
     all_extension_frames_.erase(frame);
 
     FOR_EACH_OBSERVER(ProcessManagerObserver,
                       observer_list_,
                       OnExtensionFrameUnregistered(extension_id,
                                                    render_frame_host));
@@ skipping 251 matching lines @@
                  extension_id,
                  sequence_id),
       base::TimeDelta::FromMilliseconds(g_event_page_suspending_time_msec));
 }
 
 void ProcessManager::OnNetworkRequestStarted(
     content::RenderFrameHost* render_frame_host,
     uint64_t request_id) {
   ExtensionHost* host = GetBackgroundHostForExtension(
       GetExtensionID(render_frame_host));
-  auto result = pending_network_requests_.insert(request_id);
+  if (!host || !IsFrameInExtensionHost(host, render_frame_host))
+    return;
+
+  auto result =
+      pending_network_requests_.insert(std::make_pair(request_id, host));
   DCHECK(result.second) << "Duplicate network request IDs.";
-  if (host && IsFrameInExtensionHost(host, render_frame_host)) {
-    IncrementLazyKeepaliveCount(host->extension());
-    host->OnNetworkRequestStarted(request_id);
-  }
+
+  IncrementLazyKeepaliveCount(host->extension());
+  host->OnNetworkRequestStarted(request_id);
 }
 
 void ProcessManager::OnNetworkRequestDone(
     content::RenderFrameHost* render_frame_host,
     uint64_t request_id) {
-  ExtensionHost* host = GetBackgroundHostForExtension(
-      GetExtensionID(render_frame_host));
-  if (host && IsFrameInExtensionHost(host, render_frame_host)) {
-    host->OnNetworkRequestDone(request_id);
-    if (pending_network_requests_.erase(request_id))
-      DecrementLazyKeepaliveCount(host->extension());
-  }
+  auto result = pending_network_requests_.find(request_id);
+  if (result == pending_network_requests_.end())
+    return;
+
+  ExtensionHost* host = result->second;

[Devlin, 2016/06/01 21:39:02]

It might be worth noting that |host| can be invalid here (I know that's why
you're checking on line 592, but future us might not remember that it's unsafe
to access this on line 590 ;))

[nasko, 2016/06/01 23:17:51]

Done.

+  pending_network_requests_.erase(result);
+
+  if (background_hosts_.find(host) == background_hosts_.end())
+    return;
+
+  DCHECK(IsFrameInExtensionHost(host, render_frame_host));
+
+  host->OnNetworkRequestDone(request_id);
+  DecrementLazyKeepaliveCount(host->extension());
 }
 
 void ProcessManager::CancelSuspend(const Extension* extension) {
   bool& is_closing = background_page_data_[extension->id()].is_closing;
   ExtensionHost* host = GetBackgroundHostForExtension(extension->id());
   if (host && is_closing) {
     is_closing = false;
     host->render_process_host()->Send(
         new ExtensionMsg_CancelSuspend(extension->id()));
     // This increment / decrement is to simulate an instantaneous event. This
@@ skipping 377 matching lines @@
   if (extension && !IncognitoInfo::IsSplitMode(extension)) {
     BrowserContext* original_context =
         ExtensionsBrowserClient::Get()->GetOriginalContext(browser_context());
     return ProcessManager::Get(original_context)->GetSiteInstanceForURL(url);
   }
 
   return ProcessManager::GetSiteInstanceForURL(url);
 }
 
 }  // namespace extensions