Declarative content scripts: Browser-side: per-extension shared memory regions (lazily loaded)

chrome/browser/extensions/declarative_user_script_master.cc

+// Copyright (c) 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 "chrome/browser/extensions/declarative_user_script_master.h"
+
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/extensions/extension_util.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/extensions/api/i18n/default_locale_handler.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/render_process_host.h"
+#include "extensions/browser/content_verifier.h"
+#include "extensions/browser/extension_system.h"
+
+namespace extensions {
+
+DeclarativeUserScriptMaster::DeclarativeUserScriptMaster(
+    Profile* profile,
+    const ExtensionId& extension_id)
+    : UserScriptMaster(profile) {
+  owner_extension_id_ = extension_id;

[Devlin, 2014/07/30 21:20:38]

init this in the initialization list.

[Mark Dittmer, 2014/07/31 18:37:33]

Done.

+  registrar_.Add(this,
+                 content::NOTIFICATION_RENDERER_PROCESS_CREATED,
+                 content::NotificationService::AllBrowserContextsAndSources());
+}
+
+DeclarativeUserScriptMaster::~DeclarativeUserScriptMaster() {
+}
+
+void DeclarativeUserScriptMaster::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {

[Devlin, 2014/07/30 21:20:38]

If you only expect one notification, it's cleaner to do:
DCHECK_EQ(NOTIFICATION_TYPE, type);

[Mark Dittmer, 2014/07/31 18:37:33]

Done.

+    case content::NOTIFICATION_RENDERER_PROCESS_CREATED: {
+      content::RenderProcessHost* process =
+          content::Source<content::RenderProcessHost>(source).ptr();
+      Profile* profile =
+          Profile::FromBrowserContext(process->GetBrowserContext());
+      if (!profile_->IsSameProfile(profile))
+        return;
+      if (ScriptsReady()) {
+        std::set<ExtensionId> changed_extensions;
+        changed_extensions.insert(owner_extension_id_);
+        SendUpdate(process, GetSharedMemory(), changed_extensions);
+      }
+      break;
+    }
+    default:
+      DCHECK(false);

[Devlin, 2014/07/30 21:20:38]

We usually spell this NOTREACHED(). (though moot with above comment)

[Mark Dittmer, 2014/07/31 18:37:33]

Acknowledged.

+  }
+}
+
+void DeclarativeUserScriptMaster::AddScript(const UserScript& script) {
+  scripts_to_add_.insert(script);
+  if (is_loading()) {

[Devlin, 2014/07/30 21:20:38]

if (IsSingleLineIfStatement())
  RemoveBrackets();

+    ResetPendingLoad();
+  } else {
+    StartLoad();
+  }
+}
+
+void DeclarativeUserScriptMaster::RemoveScript(const UserScript& script) {
+  if (scripts_to_add_.find(script) != scripts_to_add_.end()) {

[Devlin, 2014/07/30 21:20:38]

brackets

[Devlin, 2014/07/30 21:20:38]

For sets, prefer:
if (scripts_to_add_.count(script) != 0)
...

[Mark Dittmer, 2014/07/31 18:37:33]

Done.

+    scripts_to_add_.erase(script);
+  } else {
+    scripts_to_remove_.insert(script);
+  }
+  if (is_loading()) {
+    ResetPendingLoad();
+  } else {
+    StartLoad();
+  }
+}
+
+void DeclarativeUserScriptMaster::ClearScripts() {
+  clear_scripts_ = true;
+  scripts_to_add_.clear();
+  scripts_to_remove_.clear();
+  if (is_loading()) {
+    ResetPendingLoad();
+  } else {
+    StartLoad();
+  }
+}
+
+void DeclarativeUserScriptMaster::StartLoad() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(!is_loading());
+
+  if (clear_scripts_) {
+    user_scripts_->clear();
+  }
+  bool incognito_enabled =
+      util::IsIncognitoEnabled(owner_extension_id_, profile_);
+  std::set<UserScript> new_user_scripts;
+  new_user_scripts.insert(user_scripts_->begin(), user_scripts_->end());
+  new_user_scripts.erase(scripts_to_remove_.begin(), scripts_to_remove_.end());

[Mark Dittmer, 2014/07/31 18:37:32]

This is wrong because std::set::erase cannot take input iterators from another
collection. Fixed with iteration over scripts_to_remove_ and repeated calls to
erase(*scripts_to_remove_iterator).

+  for (std::set<UserScript>::const_iterator it = scripts_to_add_.begin();
+       it != scripts_to_add_.end();
+       ++it) {
+    UserScript script = *it;
+    script.set_incognito_enabled(incognito_enabled);
+    new_user_scripts.insert(script);
+  }
+  user_scripts_->assign(new_user_scripts.begin(), new_user_scripts.end());
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::FILE,
+      FROM_HERE,
+      base::Bind(&UserScriptMaster::LoadScriptsOnFileThread,
+                 base::Passed(&user_scripts_),
+                 extensions_info_,
+                 added_extensions_,
+                 make_scoped_refptr(
+                     ExtensionSystem::Get(profile_)->content_verifier()),
+                 base::Bind(&UserScriptMaster::OnScriptsLoaded,
+                            weak_factory_.GetWeakPtr())));
+
+  // File thread handler has ownership of user_scripts_ until it is given back
+  // in UserScriptMaster::OnScriptsLoaded().
+  user_scripts_.reset(NULL);
+
+  ResetPendingLoadData();
+}
+
+}  // namespace extensions