Add setting to isolate zoom changes by default.

chrome/browser/ui/zoom/chrome_zoom_level_prefs.h

Index: chrome/browser/ui/zoom/chrome_zoom_level_prefs.h
diff --git a/chrome/browser/ui/zoom/chrome_zoom_level_prefs.h b/chrome/browser/ui/zoom/chrome_zoom_level_prefs.h
index 4799e23f1ccbadbca9c41d970a89f55e60bbeb4d..bae6c38156f61a27ed0f60effefcf7dd87112e98 100644
--- a/chrome/browser/ui/zoom/chrome_zoom_level_prefs.h
+++ b/chrome/browser/ui/zoom/chrome_zoom_level_prefs.h
@@ -11,12 +11,10 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
-#include "components/prefs/json_pref_store.h"
-#include "components/prefs/pref_change_registrar.h"
+#include "chrome/browser/ui/zoom/chrome_zoom_prefs_helper.h"
 #include "components/prefs/pref_service.h"
-#include "components/prefs/pref_store.h"
+#include "components/zoom/zoom_prefs_delegate.h"
 #include "content/public/browser/host_zoom_map.h"
-#include "content/public/browser/zoom_level_delegate.h"
 
 namespace base {
 class DictionaryValue;
@@ -26,20 +24,23 @@ namespace zoom {
 class ZoomEventManager;
 }
 
-// A class to manage per-partition default and per-host zoom levels in Chrome's
-// preference system. It implements an interface between the content/ zoom
-// levels in HostZoomMap and Chrome's preference system. All changes
-// to the per-partition default zoom levels from chrome/ flow through this
+// A class to manage per-partition default and per-host zoom levels as well as
+// the zoom scope pref in Chrome's preference system. It implements an
+// interface to Chrome's preference system for the content/ zoom levels in
+// HostZoomMap and the zoom scope in ZoomController. All changes to the
+// per-partition default zoom levels and scope from chrome/ flow through this
 // class. Any changes to per-host levels are updated when HostZoomMap calls
 // OnZoomLevelChanged.
-class ChromeZoomLevelPrefs : public content::ZoomLevelDelegate {
+class ChromeZoomLevelPrefs : public zoom::ZoomPrefsDelegate {
  public:
   typedef base::CallbackList<void(void)>::Subscription
       DefaultZoomLevelSubscription;
 
-  // Initialize the pref_service and the partition_key via the constructor,
-  // as these concepts won't be available in the content base class
-  // ZoomLevelDelegate, which will define the InitHostZoomMap interface.
+  // Initialize our ChromeZoomPrefsHelper with pref_service and the partition
+  // information via this constructor, as these concepts won't be available in
+  // the content base class ZoomLevelDelegate (which will define the
+  // InitHostZoomMap interface) nor in the components class ZoomPrefsDelegate
+  // (which will define the interface for the zoom scope pref).
   // |pref_service_| must outlive this class.
   ChromeZoomLevelPrefs(
       PrefService* pref_service,
@@ -55,25 +56,31 @@ class ChromeZoomLevelPrefs : public content::ZoomLevelDelegate {
   std::unique_ptr<DefaultZoomLevelSubscription>
   RegisterDefaultZoomLevelCallback(const base::Closure& callback);
 
+  void SetZoomScopeIsPerOriginPref(bool is_per_origin);
+
   void ExtractPerHostZoomLevels(
       const base::DictionaryValue* host_zoom_dictionary,
       bool sanitize_partition_host_zoom_levels);
 
-  // content::ZoomLevelDelegate
+  // zoom::ZoomPrefsDelegate
   void InitHostZoomMap(content::HostZoomMap* host_zoom_map) override;
 
+  bool GetZoomScopeIsPerOriginPref() const override;
+  std::unique_ptr<DefaultZoomScopeSubscription>
+  RegisterDefaultZoomScopeCallback(const base::Closure& callback) override;
+
  private:
   // This is a callback function that receives notifications from HostZoomMap
   // when per-host zoom levels change. It is used to update the per-host
   // zoom levels (if any) managed by this class (for its associated partition).
   void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change);
 
-  PrefService* pref_service_;
+  ChromeZoomPrefsHelper partitioned_prefs_;
   base::WeakPtr<zoom::ZoomEventManager> zoom_event_manager_;
   content::HostZoomMap* host_zoom_map_;
   std::unique_ptr<content::HostZoomMap::Subscription> zoom_subscription_;
-  std::string partition_key_;
   base::CallbackList<void(void)> default_zoom_changed_callbacks_;
+  base::CallbackList<void(void)> default_scope_changed_callbacks_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeZoomLevelPrefs);
 };