ExtensionFrameHelper shouldn't trigger initialization of the main world

extensions/renderer/extension_frame_helper.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/renderer/extension_frame_helper.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
 #include "base/timer/elapsed_timer.h"
 #include "content/public/renderer/render_frame.h"
 #include "extensions/common/api/messaging/message.h"
 #include "extensions/common/api/messaging/port_id.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/manifest_handlers/background_info.h"
 #include "extensions/renderer/console.h"
 #include "extensions/renderer/content_watcher.h"
 #include "extensions/renderer/dispatcher.h"
 #include "extensions/renderer/messaging_bindings.h"
 #include "extensions/renderer/script_context.h"
 #include "third_party/WebKit/public/platform/WebSecurityOrigin.h"
 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 
 namespace extensions {
 
 namespace {
 
+constexpr int kMainWorldId = 0;

[Yuki, 2017/03/10 07:34:46]

side note: Probably, we should get rid of exposing world IDs.
+nhiroki@ FYI.

[haraken, 2017/03/10 09:17:26]

Yeah, agreed. Ideally I want to entirely remove world IDs from the embedder
side.

Alternately can we expose some public API like isMainWorld()?

+
 base::LazyInstance<std::set<const ExtensionFrameHelper*>>::DestructorAtExit
     g_frame_helpers = LAZY_INSTANCE_INITIALIZER;
 
 // Returns true if the render frame corresponding with |frame_helper| matches
 // the given criteria.
 bool RenderFrameMatches(const ExtensionFrameHelper* frame_helper,
                         ViewType match_view_type,
                         int match_window_id,
                         int match_tab_id,
                         const std::string& match_extension_id) {
@@ skipping 151 matching lines @@
     blink::WebDataSource* data_source) {
   if (!delayed_main_world_script_initialization_)
     return;
 
   delayed_main_world_script_initialization_ = false;
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   v8::Local<v8::Context> context =
       render_frame()->GetWebFrame()->mainWorldScriptContext();
   v8::Context::Scope context_scope(context);
   extension_dispatcher_->DidCreateScriptContext(render_frame()->GetWebFrame(),
-                                                context, 0);
+                                                context, kMainWorldId);
   // TODO(devlin): Add constants for main world id, no extension group.
 }
 
 void ExtensionFrameHelper::DidCreateScriptContext(
     v8::Local<v8::Context> context,
     int world_id) {
-  if (context == render_frame()->GetWebFrame()->mainWorldScriptContext() &&
+  if (world_id == kMainWorldId &&
       render_frame()->IsBrowserSideNavigationPending()) {
-    DCHECK_EQ(0, world_id);
     DCHECK(!delayed_main_world_script_initialization_);
     // Defer initializing the extensions script context now because it depends
     // on having the URL of the provisional load which isn't available at this
     // point with PlzNavigate.
     delayed_main_world_script_initialization_ = true;
   } else {
     extension_dispatcher_->DidCreateScriptContext(render_frame()->GetWebFrame(),
                                                   context, world_id);
   }
 }
@@ skipping 96 matching lines @@
     const base::ListValue& args) {
   extension_dispatcher_->InvokeModuleSystemMethod(
       render_frame(), extension_id, module_name, function_name, args);
 }
 
 void ExtensionFrameHelper::OnDestruct() {
   delete this;
 }
 
 }  // namespace extensions