Fix prefs registration in BrowserInstantController.

Registration should happen prior to PrefService construction, so accepting a PrefService parameter to RegisterUserPrefs is a no-no.

To keep the existing semantics, this change adds a PrefService::SetDefaultPrefValue method that allows you to change the default value for a pref.

As BrowserInstantController was the last method called from chrome::RegisterUserPrefs that required a PrefService pointer, this also removes the PrefService parameter from the latter function and updates callers.

TBR=ben@chromium.org
BUG=155525


Review URL: https://chromiumcodereview.appspot.com/12315116

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185712 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 32 insertions, 0 deletions

diff --git a/base/prefs/pref_registry.cc b/base/prefs/pref_registry.cc
index c6fad4e..9ca1102 100644
--- a/base/prefs/pref_registry.cc
+++ b/base/prefs/pref_registry.cc
@@ -28,6 +28,21 @@ PrefRegistry::const_iterator PrefRegistry::end() const {
   return defaults_->end();
 }
 
+void PrefRegistry::SetDefaultPrefValue(const char* pref_name,
+                                       base::Value* value) {
+  DCHECK(value);
+  if (DCHECK_IS_ON()) {
+    const base::Value* current_value = NULL;
+    DCHECK(defaults_->GetValue(pref_name, &current_value))
+        << "Setting default for unregistered pref: " << pref_name;
+    DCHECK(value->IsType(current_value->GetType()))
+        << "Wrong type for new default: " << pref_name;
+  }
+
+  defaults_->RemoveDefaultValue(pref_name);
+  defaults_->SetDefaultValue(pref_name, value);
+}
+
 void PrefRegistry::SetRegistrationCallback(
     const RegistrationCallback& callback) {
   registration_callback_ = callback;
diff --git a/base/prefs/pref_registry.h b/base/prefs/pref_registry.h
index 8f39341c..6c7eac9f 100644
--- a/base/prefs/pref_registry.h
+++ b/base/prefs/pref_registry.h
@@ -40,6 +40,11 @@ class BASE_PREFS_EXPORT PrefRegistry : public base::RefCounted<PrefRegistry> {
   const_iterator begin() const;
   const_iterator end() const;
 
+  // Changes the default value for a preference. Takes ownership of |value|.
+  //
+  // |pref_name| must be a previously registered preference.
+  void SetDefaultPrefValue(const char* pref_name, base::Value* value);
+
   // Exactly one callback can be set for registration. The callback
   // will be invoked each time registration has been performed on this
   // object.
diff --git a/base/prefs/pref_service.cc b/base/prefs/pref_service.cc
index 67ab898..b1f4f3f 100644
--- a/base/prefs/pref_service.cc
+++ b/base/prefs/pref_service.cc
@@ -273,6 +273,12 @@ const base::Value* PrefService::GetUserPrefValue(const char* path) const {
   return value;
 }
 
+void PrefService::SetDefaultPrefValue(const char* path,
+                                      base::Value* value) {
+  DCHECK(CalledOnValidThread());
+  pref_registry_->SetDefaultPrefValue(path, value);
+}
+
 const base::Value* PrefService::GetDefaultPrefValue(const char* path) const {
   DCHECK(CalledOnValidThread());
   // Lookup the preference in the default store.
diff --git a/base/prefs/pref_service.h b/base/prefs/pref_service.h
index d9cc8f5..9ba78be 100644
--- a/base/prefs/pref_service.h
+++ b/base/prefs/pref_service.h
@@ -220,6 +220,12 @@ class BASE_PREFS_EXPORT PrefService : public base::NonThreadSafe {
   // the preference is not set in the user pref store, returns NULL.
   const base::Value* GetUserPrefValue(const char* path) const;
 
+  // Changes the default value for a preference. Takes ownership of |value|.
+  //
+  // Will cause a pref change notification to be fired if this causes
+  // the effective value to change.
+  void SetDefaultPrefValue(const char* path, base::Value* value);
+
   // Returns the default value of the given preference. |path| must point to a
   // registered preference. In that case, will never return NULL.
   const base::Value* GetDefaultPrefValue(const char* path) const;