WIP: Introduce per-TabContents PrefService.

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index 159e6b8238b178369521c69321f0b76f0786777a..62a14a2f95f126fee34ea724b08c19d71c2e5087 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -96,6 +96,7 @@
 #include "content/browser/renderer_host/render_process_host.h"
 #include "content/browser/speech/speech_input_manager.h"
 #include "content/browser/ssl/ssl_host_state.h"
+#include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/user_metrics.h"
 #include "content/common/notification_service.h"
 #include "grit/browser_resources.h"
@@ -941,6 +942,21 @@ PrefService* ProfileImpl::GetOffTheRecordPrefs() {
   return otr_prefs_.get();
 }
 
+PrefService* ProfileImpl::GetPrefsForTabContents(TabContents* contents) {
+  static PropertyAccessor<PrefService*>* accessor = NULL;
+  if (!accessor)
+    accessor = new PropertyAccessor<PrefService*>;
+
+  PrefService** prefs_property =
+      accessor->GetProperty(contents->property_bag());
+  if (prefs_property && *prefs_property)
+    return *prefs_property;
+
+  PrefService* prefs = GetPrefs()->CreateTabContentsPrefService();
+  accessor->SetProperty(contents->property_bag(), prefs);
+  return prefs;
+}
+
 FilePath ProfileImpl::GetPrefFilePath() {
   FilePath pref_file_path = path_;
   pref_file_path = pref_file_path.Append(chrome::kPreferencesFilename);