Introduce per-tab preferences service.

chrome/browser/prefs/pref_service.cc

Index: chrome/browser/prefs/pref_service.cc
diff --git a/chrome/browser/prefs/pref_service.cc b/chrome/browser/prefs/pref_service.cc
index 3050a1734f410988b8ff101d0c2ec65972447e84..f64da41a4e70898677e72141db3a11443138b904 100644
--- a/chrome/browser/prefs/pref_service.cc
+++ b/chrome/browser/prefs/pref_service.cc
@@ -25,6 +25,7 @@
 #include "chrome/browser/prefs/command_line_pref_store.h"
 #include "chrome/browser/prefs/default_pref_store.h"
 #include "chrome/browser/prefs/incognito_user_pref_store.h"
+#include "chrome/browser/prefs/per_tab_user_pref_store.h"
 #include "chrome/browser/prefs/pref_model_associator.h"
 #include "chrome/browser/prefs/pref_notifier_impl.h"
 #include "chrome/browser/prefs/pref_value_store.h"
@@ -152,66 +153,77 @@ PrefService* PrefService::CreatePrefService(const FilePath& pref_filename,
   JsonPrefStore* user = new JsonPrefStore(
       pref_filename,
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
-  DefaultPrefStore* default_pref_store = new DefaultPrefStore();
+
 
   return new PrefService(
-      managed_platform, managed_cloud, extension_prefs,
-      command_line, user, recommended_platform,
-      recommended_cloud, default_pref_store, async);
+      new PrefValueStore(managed_platform,
+                         managed_cloud,
+                         extension_prefs,
+                         command_line,
+                         user,
+                         recommended_platform,
+                         recommended_cloud,
+                         new DefaultPrefStore(),
+                         new PrefModelAssociator(),
+                         new PrefNotifierImpl()),
+      async);
 }
 
 PrefService* PrefService::CreateIncognitoPrefService(
     PrefStore* incognito_extension_prefs) {
-  return new PrefService(*this, incognito_extension_prefs);
-}
-
-PrefService::PrefService(PrefStore* managed_platform_prefs,
-                         PrefStore* managed_cloud_prefs,
-                         PrefStore* extension_prefs,
-                         PrefStore* command_line_prefs,
-                         PersistentPrefStore* user_prefs,
-                         PrefStore* recommended_platform_prefs,
-                         PrefStore* recommended_cloud_prefs,
-                         DefaultPrefStore* default_store,
+  return new PrefService(
+      pref_value_store_->CloneAndSpecialize(
+          NULL, // managed_platform_prefs
+          NULL, // managed_cloud_prefs
+          incognito_extension_prefs,
+          NULL, // command_line_prefs
+          new IncognitoUserPrefStore(user_pref_store_.get()),
+          NULL, // recommended_platform_prefs
+          NULL, // recommended_cloud_prefs
+          default_store_.get(),
+          // Incognito mode doesn't sync, so no need to create
+          // PrefModelAssociator.
+          NULL, // pref_sync_associator
+          // TODO(mnissler,mnaganov): This PrefNotifier needs to listen for
+          // notifications from the original |pref_notifier_| and forward
+          // notifications. We need to implement a wrapper that does this.

[Mattias Nissler (ping if slow), 2011/11/16 12:08:04]

I originally thought this would be a problem, but it actually isn't since
PrefValueStore will listen to pref changes happening in the PrefStores and
forward the notifications to the correct PrefNotifier. Hence, you can just
remove the comment :)

[mnaganov (inactive), 2011/11/17 16:50:58]

Done.

+          new PrefNotifierImpl()),
+      false);
+}
+
+PrefService* PrefService::CreatePrefServiceWithPerTabPrefStore() {
+  return new PrefService(
+      pref_value_store_->CloneAndSpecialize(
+          NULL, // managed_platform_prefs
+          NULL, // managed_cloud_prefs
+          NULL, // extension_prefs
+          NULL, // command_line_prefs
+          new PerTabUserPrefStore(user_pref_store_.get()),
+          NULL, // recommended_platform_prefs
+          NULL, // recommended_cloud_prefs
+          new DefaultPrefStore(),
+          NULL, // pref_sync_associator
+          new PrefNotifierImpl()),
+      false);
+}
+
+PrefService::PrefService(PrefValueStore* pref_value_store,
                          bool async)
-    : user_pref_store_(user_prefs),
-      default_store_(default_store) {
-  pref_sync_associator_.reset(new PrefModelAssociator(this));
-  pref_notifier_.reset(new PrefNotifierImpl(this));
-  pref_value_store_.reset(
-      new PrefValueStore(managed_platform_prefs,
-                         managed_cloud_prefs,
-                         extension_prefs,
-                         command_line_prefs,
-                         user_pref_store_,
-                         recommended_platform_prefs,
-                         recommended_cloud_prefs,
-                         default_store,
-                         pref_sync_associator_.get(),
-                         pref_notifier_.get()));
+    : pref_value_store_(pref_value_store),
+      pref_notifier_(reinterpret_cast<PrefNotifierImpl*>(
+          pref_value_store_->pref_notifier_)),

[Mattias Nissler (ping if slow), 2011/11/16 12:08:04]

Suggestion: To avoid this cast, maybe it's better to instantiate
PrefNotifierImpl here, and have a set_pref_notifier() call on PrefValueStore?

[mnaganov (inactive), 2011/11/17 16:50:58]

I've reconsidered the approach to PrefService initialization, now it looks
prettier.

+      user_pref_store_(reinterpret_cast<PersistentPrefStore*>(
+          pref_value_store_->GetPrefStore(PrefValueStore::USER_STORE))),

[Mattias Nissler (ping if slow), 2011/11/16 12:08:04]

These casts suck. Can we just pass on the properly-typed pointers to the
constructor?

[mnaganov (inactive), 2011/11/17 16:50:58]

Fixed.

+      default_store_(reinterpret_cast<DefaultPrefStore*>(
+          pref_value_store_->GetPrefStore(PrefValueStore::DEFAULT_STORE))),
+      pref_sync_associator_(pref_value_store_->pref_sync_associator_) {

[Mattias Nissler (ping if slow), 2011/11/16 12:08:04]

This seems weird. Pass it in a parameter?

[mnaganov (inactive), 2011/11/17 16:50:58]

Fixed.

+  pref_notifier_->SetPrefService(this);
+  if (pref_sync_associator_.get())
+    pref_sync_associator_->SetPrefService(this);
+  pref_notifier_->SetPrefModelAssociator(pref_sync_associator_.get());
   InitFromStorage(async);
 }
 
-PrefService::PrefService(const PrefService& original,
-                         PrefStore* incognito_extension_prefs)
-      : user_pref_store_(
-            new IncognitoUserPrefStore(original.user_pref_store_.get())),
-        default_store_(original.default_store_.get()) {
-  // Incognito mode doesn't sync, so no need to create PrefModelAssociator.
-  pref_notifier_.reset(new PrefNotifierImpl(this));
-  pref_value_store_.reset(original.pref_value_store_->CloneAndSpecialize(
-      NULL, // managed_platform_prefs
-      NULL, // managed_cloud_prefs
-      incognito_extension_prefs,
-      NULL, // command_line_prefs
-      user_pref_store_.get(),
-      NULL, // recommended_platform_prefs
-      NULL, // recommended_cloud_prefs
-      default_store_.get(),
-      NULL, // pref_sync_associator_
-      pref_notifier_.get()));
-}
-
 PrefService::~PrefService() {
   DCHECK(CalledOnValidThread());
   STLDeleteContainerPointers(prefs_.begin(), prefs_.end());