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

chrome/browser/profiles/profile.h

Index: chrome/browser/profiles/profile.h
diff --git a/chrome/browser/profiles/profile.h b/chrome/browser/profiles/profile.h
index 87a4c5fd6c31906e0bcfbec6026d9a7c52d9360e..931442e7681cc7805ff8984b84594b5a00658c65 100644
--- a/chrome/browser/profiles/profile.h
+++ b/chrome/browser/profiles/profile.h
@@ -218,6 +218,11 @@ class Profile : public content::BrowserContext {
   // preferences for this user profile.
   virtual PrefService* GetPrefs() = 0;
 
+  // Retrieves a pointer to the PrefService that manages the default zoom
+  // level and the per-host zoom levels for this user profile.
+  // TODO(wjmaclean): Remove this when HostZoomMap migrates to StoragePartition.
+  virtual PrefService* GetZoomLevelPrefs();

[Bernhard Bauer, 2014/09/12 10:28:49]

Instead of adding a new method to Profile, could you make this a KeyedService?

[wjmaclean, 2014/09/16 18:44:44]

I could make it a keyede service, but hopefully this will be removed within a
week (or at most two) from when this CL lands, so is it worth it?

+
   // Retrieves a pointer to the PrefService that manages the preferences
   // for OffTheRecord Profiles.  This PrefService is lazily created the first
   // time that this method is called.