[DevTools] Split DevToolsHttpHandler into two classes

extensions/shell/browser/shell_browser_main_parts.cc

Index: extensions/shell/browser/shell_browser_main_parts.cc
diff --git a/extensions/shell/browser/shell_browser_main_parts.cc b/extensions/shell/browser/shell_browser_main_parts.cc
index 7681b660408ce53a1f0c3ec5c516f40a4355d1b8..0e22cbcc8436b1da42849e74028f8a173041579d 100644
--- a/extensions/shell/browser/shell_browser_main_parts.cc
+++ b/extensions/shell/browser/shell_browser_main_parts.cc
@@ -71,10 +71,7 @@ ShellBrowserMainParts::ShellBrowserMainParts(
 }
 
 ShellBrowserMainParts::~ShellBrowserMainParts() {
-  if (devtools_http_handler_) {
-    // Note that Stop destroys devtools_http_handler_.
-    devtools_http_handler_->Stop();
-  }
+  DCHECK(!devtools_http_handler_);
 }
 
 void ShellBrowserMainParts::PreMainMessageLoopStart() {
@@ -214,6 +211,11 @@ void ShellBrowserMainParts::PostMainMessageLoopRun() {
   extension_system_ = NULL;
   ExtensionsBrowserClient::Set(NULL);
   extensions_browser_client_.reset();
+  if (devtools_http_handler_) {

[James Cook, 2014/11/11 18:32:31]

If possible please move this to immediately after
browser_main_delegate_->Shutdown() so that the various services are shut down
and deleted in the opposite order to which they are created.

If you can't do that, please add a comment explaining why it must be destroyed
in this order.

[vkuzkokov, 2014/11/12 09:41:20]

Moved.

+    // Note that Stop destroys devtools_http_handler_.
+    devtools_http_handler_->Stop();
+    devtools_http_handler_ = nullptr;
+  }
   browser_context_.reset();
 
   desktop_controller_.reset();