Introduce ChromeZoomLevelPref, make zoom level prefs independent of profile prefs.

chrome/browser/ui/prefs/prefs_tab_helper.cc

Index: chrome/browser/ui/prefs/prefs_tab_helper.cc
diff --git a/chrome/browser/ui/prefs/prefs_tab_helper.cc b/chrome/browser/ui/prefs/prefs_tab_helper.cc
index 816e08b60f60092d0f97371f9dc9d6261dbc86bb..df0c6ad94b8064406368af25ad2c53171d6dab69 100644
--- a/chrome/browser/ui/prefs/prefs_tab_helper.cc
+++ b/chrome/browser/ui/prefs/prefs_tab_helper.cc
@@ -15,15 +15,18 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_preferences_util.h"
+#include "chrome/browser/ui/zoom/zoom_controller.h"
 #include "chrome/common/pref_font_webkit_names.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/pref_names_util.h"
 #include "chrome/grit/locale_settings.h"
 #include "components/pref_registry/pref_registry_syncable.h"
+#include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/renderer_preferences.h"
 #include "content/public/common/web_preferences.h"
 #include "grit/platform_locale_settings.h"
 #include "third_party/icu/source/common/unicode/uchar.h"
@@ -310,18 +313,50 @@ void OverrideFontFamily(WebPreferences* prefs,
   (*map)[script] = base::UTF8ToUTF16(pref_value);
 }
 
+double GetDefaultZoomLevel(const content::WebContents* web_contents) {
+  const ZoomController* zoom_controller =
+      ZoomController::FromWebContents(web_contents);
+  if (zoom_controller)
+    return zoom_controller->GetDefaultZoomLevel();
+  return content::HostZoomMap::GetDefaultForBrowserContext(
+             web_contents->GetBrowserContext())->GetDefaultZoomLevel();
+}
+
 }  // namespace
 
 PrefsTabHelper::PrefsTabHelper(WebContents* contents)
     : web_contents_(contents),
       weak_ptr_factory_(this) {
+  // TODO(wjmaclean): Convert this to use the content-specific zoom-level
+  // prefs when HostZoomMap moves to StoragePartition.
+  PrefService* zoom_level_prefs = GetProfile()->GetZoomLevelPrefs();
+  if (zoom_level_prefs) {
+    zoom_level_pref_change_registrar_.Init(zoom_level_prefs);
+    base::Closure renderer_callback = base::Bind(
+        &PrefsTabHelper::UpdateRendererPreferences, base::Unretained(this));
+    zoom_level_pref_change_registrar_.Add(prefs::kDefaultZoomLevel,
+                                          renderer_callback);
+    if (zoom_level_prefs->GetInitializationStatus() ==
+        PrefService::INITIALIZATION_STATUS_WAITING) {
+      // Unlike per-profile prefs, which are guaranteed to have initialized by
+      // the time we get here, zoom-level prefs may not have
+      // completed their initialization. In this case, we need to re-sync the
+      // renderer prefs once their initialization completes so that the default
+      // zoom level information is updated.
+      // We bind to a WeakPtr in case 'this' disappears before the pref store
+      // calls the observer, e.g. shutting down Chrome during startup?
+      zoom_level_prefs->AddPrefInitObserver(
+          base::Bind(&PrefsTabHelper::UpdateAfterZoomLevelPrefsInitialized,
+                     weak_ptr_factory_.GetWeakPtr()));
+    }
+  }
+
   PrefService* prefs = GetProfile()->GetPrefs();
   pref_change_registrar_.Init(prefs);
   if (prefs) {
     base::Closure renderer_callback = base::Bind(
         &PrefsTabHelper::UpdateRendererPreferences, base::Unretained(this));
     pref_change_registrar_.Add(prefs::kAcceptLanguages, renderer_callback);
-    pref_change_registrar_.Add(prefs::kDefaultZoomLevel, renderer_callback);
     pref_change_registrar_.Add(prefs::kEnableDoNotTrack, renderer_callback);
     pref_change_registrar_.Add(prefs::kEnableReferrers, renderer_callback);
 
@@ -359,13 +394,18 @@ PrefsTabHelper::PrefsTabHelper(WebContents* contents)
                                   webkit_callback);
   }
 
-  renderer_preferences_util::UpdateFromSystemSettings(
-      web_contents_->GetMutableRendererPrefs(), GetProfile());
+  content::RendererPreferences* render_prefs =
+      web_contents_->GetMutableRendererPrefs();
+  renderer_preferences_util::UpdateFromSystemSettings(render_prefs,
+                                                      GetProfile());
+  render_prefs->default_zoom_level = GetDefaultZoomLevel(web_contents_);
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && defined(ENABLE_THEMES)
-  registrar_.Add(this, chrome::NOTIFICATION_BROWSER_THEME_CHANGED,
-                 content::Source<ThemeService>(
-                     ThemeServiceFactory::GetForProfile(GetProfile())));
+            registrar_.Add(
+                this,
+                chrome::NOTIFICATION_BROWSER_THEME_CHANGED,
+                content::Source<ThemeService>(
+                    ThemeServiceFactory::GetForProfile(GetProfile())));
 #endif
 #if defined(USE_AURA)
   registrar_.Add(this,
@@ -566,9 +606,16 @@ void PrefsTabHelper::UpdateWebPreferences() {
       web_contents_->GetRenderViewHost()->GetWebkitPreferences());
 }
 
+void PrefsTabHelper::UpdateAfterZoomLevelPrefsInitialized(bool success) {
+  if (success)
+    UpdateRendererPreferences();
+}
+
 void PrefsTabHelper::UpdateRendererPreferences() {
-  renderer_preferences_util::UpdateFromSystemSettings(
-      web_contents_->GetMutableRendererPrefs(), GetProfile());
+  content::RendererPreferences* prefs =
+      web_contents_->GetMutableRendererPrefs();
+  renderer_preferences_util::UpdateFromSystemSettings(prefs, GetProfile());
+  prefs->default_zoom_level = GetDefaultZoomLevel(web_contents_);
   web_contents_->GetRenderViewHost()->SyncRendererPrefs();
 }