Renderer changes for wiring up shared memory with declarative injection

extensions/renderer/user_script_set_manager.cc

 // Copyright 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 "extensions/renderer/user_script_set_manager.h"
 
 #include "components/crx_file/id_util.h"
 #include "content/public/renderer/render_thread.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/renderer/dispatcher.h"
@@ skipping 13 matching lines @@
 }
 
 void UserScriptSetManager::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
 
 void UserScriptSetManager::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
+scoped_ptr<ScriptInjection>
+UserScriptSetManager::GetInjectionForDeclarativeScript(
+    int64 script_id,
+    blink::WebFrame* web_frame,
+    int tab_id,
+    const GURL& url,
+    const Extension* extension) {
+  UserScriptSet* user_script_set =
+      GetProgrammaticScriptsByExtension(extension->id());
+  if (!user_script_set)
+    return scoped_ptr<ScriptInjection>();
+
+  return user_script_set->GetDeclarativeScriptInjection(
+      script_id,
+      web_frame,
+      tab_id,
+      UserScript::BROWSER_DRIVEN,
+      url,
+      extension);
+}
+
 bool UserScriptSetManager::OnControlMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(UserScriptSetManager, message)
     IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateUserScripts, OnUpdateUserScripts)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
-const UserScriptSet* UserScriptSetManager::GetProgrammaticScriptsByExtension(
-    const ExtensionId& extension_id) {
-  UserScriptSetMap::const_iterator it =
-      programmatic_scripts_.find(extension_id);
-  return it != programmatic_scripts_.end() ? it->second.get() : NULL;
-}
-
 void UserScriptSetManager::GetAllInjections(
     ScopedVector<ScriptInjection>* injections,
     blink::WebFrame* web_frame,
     int tab_id,
     UserScript::RunLocation run_location) {
   static_scripts_.GetInjections(injections, web_frame, tab_id, run_location);
   for (UserScriptSetMap::iterator it = programmatic_scripts_.begin();
        it != programmatic_scripts_.end();
        ++it) {
     it->second->GetInjections(injections, web_frame, tab_id, run_location);
   }
 }
 
 void UserScriptSetManager::GetAllActiveExtensionIds(
     std::set<std::string>* ids) const {
   DCHECK(ids);
   static_scripts_.GetActiveExtensionIds(ids);
   for (UserScriptSetMap::const_iterator it = programmatic_scripts_.begin();
        it != programmatic_scripts_.end();
        ++it) {
     it->second->GetActiveExtensionIds(ids);
   }
 }
 
+UserScriptSet* UserScriptSetManager::GetProgrammaticScriptsByExtension(
+    const ExtensionId& extension_id) {
+  UserScriptSetMap::const_iterator it =
+      programmatic_scripts_.find(extension_id);
+  return it != programmatic_scripts_.end() ? it->second.get() : NULL;
+}
+
 void UserScriptSetManager::OnUpdateUserScripts(
     base::SharedMemoryHandle shared_memory,
     const ExtensionId& extension_id,
     const std::set<std::string>& changed_extensions) {
   if (!base::SharedMemory::IsHandleValid(shared_memory)) {
     NOTREACHED() << "Bad scripts handle";
     return;
   }
 
   for (std::set<std::string>::const_iterator iter = changed_extensions.begin();
        iter != changed_extensions.end();
        ++iter) {
     if (!crx_file::id_util::IdIsValid(*iter)) {
       NOTREACHED() << "Invalid extension id: " << *iter;
       return;
     }
   }
 
   UserScriptSet* scripts = NULL;
   if (!extension_id.empty()) {
-    // The expectation when there is an extensions that "owns" this shared
-    // memory region is that it will list itself as the only changed extension.
-    CHECK(changed_extensions.size() == 1 &&
-          changed_extensions.find(extension_id) != changed_extensions.end());
+    // The expectation when there is an extension that "owns" this shared
+    // memory region is that the |changed_extensions| is either the empty list
+    // or just the owner.
+    CHECK(changed_extensions.size() <= 1);
     if (programmatic_scripts_.find(extension_id) ==
         programmatic_scripts_.end()) {
       scripts = new UserScriptSet(extensions_);
       programmatic_scripts_[extension_id] = make_linked_ptr(scripts);
     } else {
       scripts = programmatic_scripts_[extension_id].get();
     }
   } else {
     scripts = &static_scripts_;
   }
   DCHECK(scripts);
 
   // If no extensions are included in the set, that indicates that all
   // extensions were updated. Add them all to the set so that observers and
   // individual UserScriptSets don't need to know this detail.
   const std::set<std::string>* effective_extensions = &changed_extensions;
   std::set<std::string> all_extensions;
   if (changed_extensions.empty()) {
-    all_extensions = extensions_->GetIDs();
+    // The meaning of "all extensions" varies, depending on whether some
+    // extension "owns" this shared memory region.
+    // No owner => all known extensions.
+    // Owner    => just the owner extension.
+    if (extension_id.empty())
+      all_extensions = extensions_->GetIDs();
+    else
+      all_extensions.insert(extension_id);
     effective_extensions = &all_extensions;
   }
 
   if (scripts->UpdateUserScripts(shared_memory, *effective_extensions)) {
     FOR_EACH_OBSERVER(
         Observer,
         observers_,
         OnUserScriptsUpdated(*effective_extensions, scripts->scripts()));
   }
 }
 
 }  // namespace extensions