Don't derive from ChromeURLDataManager::DataSource, and instead have these classes implement a dele…

chrome/browser/ui/webui/chrome_url_data_manager.cc

 // Copyright (c) 2012 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/ui/webui/chrome_url_data_manager.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/i18n/rtl.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "base/synchronization/lock.h"
 #include "base/values.h"
 #include "chrome/browser/net/chrome_url_request_context.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager_factory.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager_backend.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/url_data_source_delegate.h"
 #include "grit/platform_locale_settings.h"
 #include "ui/base/l10n/l10n_util.h"
 
 #if defined (TOOLKIT_GTK)
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/font.h"
 #endif
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
 using content::BrowserThread;
 
 static base::LazyInstance<base::Lock>::Leaky
     g_delete_lock = LAZY_INSTANCE_INITIALIZER;
 
 // static
-ChromeURLDataManager::DataSources* ChromeURLDataManager::data_sources_ = NULL;
+ChromeURLDataManager::URLDataSources* ChromeURLDataManager::data_sources_ = NULL;
 
 // Invoked on the IO thread to do the actual adding of the DataSource.
 static void AddDataSourceOnIOThread(
     const base::Callback<ChromeURLDataManagerBackend*(void)>& backend,
-    scoped_refptr<ChromeURLDataManager::DataSource> data_source) {
+    scoped_refptr<URLDataSource> data_source) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   backend.Run()->AddDataSource(data_source.get());
 }
 
 ChromeURLDataManager::ChromeURLDataManager(
       const base::Callback<ChromeURLDataManagerBackend*(void)>& backend)
     : backend_(backend) {
 }
 
 ChromeURLDataManager::~ChromeURLDataManager() {
 }
 
-void ChromeURLDataManager::AddDataSource(DataSource* source) {
+void ChromeURLDataManager::AddDataSource(URLDataSource* source) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&AddDataSourceOnIOThread,
                  backend_, make_scoped_refptr(source)));
 }
 
 // static
 void ChromeURLDataManager::DeleteDataSources() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DataSources sources;
+  URLDataSources sources;
   {
     base::AutoLock lock(g_delete_lock.Get());
     if (!data_sources_)
       return;
     data_sources_->swap(sources);
   }
   for (size_t i = 0; i < sources.size(); ++i)
     delete sources[i];
 }
 
 // static
-void ChromeURLDataManager::DeleteDataSource(const DataSource* data_source) {
+void ChromeURLDataManager::DeleteDataSource(const URLDataSource* data_source) {
   // Invoked when a DataSource is no longer referenced and needs to be deleted.
   if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     // We're on the UI thread, delete right away.
     delete data_source;
     return;
   }
 
   // We're not on the UI thread, add the DataSource to the list of DataSources
   // to delete.
   bool schedule_delete = false;
   {
     base::AutoLock lock(g_delete_lock.Get());
     if (!data_sources_)
-      data_sources_ = new DataSources();
+      data_sources_ = new URLDataSources();
     schedule_delete = data_sources_->empty();
     data_sources_->push_back(data_source);
   }
   if (schedule_delete) {
     // Schedule a task to delete the DataSource back on the UI thread.
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         base::Bind(&ChromeURLDataManager::DeleteDataSources));
   }
 }
 
 // static
-void ChromeURLDataManager::AddDataSource(Profile* profile, DataSource* source) {
-  ChromeURLDataManagerFactory::GetForProfile(profile)->AddDataSource(source);
+void ChromeURLDataManager::AddDataSource(
+    Profile* profile,
+    content::URLDataSourceDelegate* delegate) {
+  if (!delegate->url_data_source_) {
+  delegate->url_data_source_ = new URLDataSource(
+      delegate->GetSource(), delegate);
+  }
+  ChromeURLDataManagerFactory::GetForProfile(profile)->AddDataSource(
+      delegate->url_data_source_);
 }
 
 // static
 bool ChromeURLDataManager::IsScheduledForDeletion(
-    const DataSource* data_source) {
+    const URLDataSource* data_source) {
   base::AutoLock lock(g_delete_lock.Get());
   if (!data_sources_)
     return false;
   return std::find(data_sources_->begin(), data_sources_->end(), data_source) !=
       data_sources_->end();
 }
 
-ChromeURLDataManager::DataSource::DataSource(const std::string& source_name,
-                                             MessageLoop* message_loop)
+URLDataSource::URLDataSource(const std::string& source_name,
+                             content::URLDataSourceDelegate* delegate)
     : source_name_(source_name),
-      message_loop_(message_loop),
-      backend_(NULL) {
+      backend_(NULL),
+      delegate_(delegate) {
 }
 
-ChromeURLDataManager::DataSource::~DataSource() {
+URLDataSource::~URLDataSource() {
 }
 
-void ChromeURLDataManager::DataSource::SendResponse(
+void URLDataSource::SendResponse(
     int request_id,
     base::RefCountedMemory* bytes) {
   // Take a ref-pointer on entry so byte->Release() will always get called.
   scoped_refptr<base::RefCountedMemory> bytes_ptr(bytes);
-  if (IsScheduledForDeletion(this)) {
+  if (ChromeURLDataManager::IsScheduledForDeletion(this)) {
     // We're scheduled for deletion. Servicing the request would result in
     // this->AddRef being invoked, even though the ref count is 0 and 'this' is
     // about to be deleted. If the AddRef were allowed through, when 'this' is
     // released it would be deleted again.
     //
     // This scenario occurs with DataSources that make history requests. Such
     // DataSources do a history query in |StartDataRequest| and the request is
     // live until the object is deleted (history requests don't up the ref
     // count). This means it's entirely possible for the DataSource to invoke
     // |SendResponse| between the time when there are no more refs and the time
     // when the object is deleted.
     return;
   }
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
-      base::Bind(&DataSource::SendResponseOnIOThread, this, request_id,
+      base::Bind(&URLDataSource::SendResponseOnIOThread, this, request_id,
                  bytes_ptr));
 }
 
-MessageLoop* ChromeURLDataManager::DataSource::MessageLoopForRequestPath(
-    const std::string& path) const {
-  return message_loop_;
-}
-
-bool ChromeURLDataManager::DataSource::ShouldReplaceExistingSource() const {
-  return true;
-}
-
-bool ChromeURLDataManager::DataSource::AllowCaching() const { return true; }
-
 // static
-void ChromeURLDataManager::DataSource::SetFontAndTextDirection(
+void URLDataSource::SetFontAndTextDirection(
     DictionaryValue* localized_strings) {
   int web_font_family_id = IDS_WEB_FONT_FAMILY;
   int web_font_size_id = IDS_WEB_FONT_SIZE;
 #if defined(OS_WIN)
   // Vary font settings for Windows XP.
   if (base::win::GetVersion() < base::win::VERSION_VISTA) {
     web_font_family_id = IDS_WEB_FONT_FAMILY_XP;
     web_font_size_id = IDS_WEB_FONT_SIZE_XP;
   }
 #endif
 
   std::string font_family = l10n_util::GetStringUTF8(web_font_family_id);
 
 #if defined(TOOLKIT_GTK)
   // Use the system font on Linux/GTK. Keep the hard-coded font families as
   // backup in case for some crazy reason this one isn't available.
   font_family = ui::ResourceBundle::GetSharedInstance().GetFont(
       ui::ResourceBundle::BaseFont).GetFontName() + ", " + font_family;
 #endif
 
   localized_strings->SetString("fontfamily", font_family);
   localized_strings->SetString("fontsize",
       l10n_util::GetStringUTF8(web_font_size_id));
   localized_strings->SetString("textdirection",
       base::i18n::IsRTL() ? "rtl" : "ltr");
 }
 
-void ChromeURLDataManager::DataSource::SendResponseOnIOThread(
+void URLDataSource::SendResponseOnIOThread(
     int request_id,
     scoped_refptr<base::RefCountedMemory> bytes) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (backend_)
     backend_->DataAvailable(request_id, bytes);
 }