Migrate HostZoomMap to live in StoragePartition.

content/public/browser/browser_context.h

Index: content/public/browser/browser_context.h
diff --git a/content/public/browser/browser_context.h b/content/public/browser/browser_context.h
index 147eab32d612742989f1c7045be97ff0ef926bd6..c039dcf40da0ad983c0a80a7eb08395eaa530354 100644
--- a/content/public/browser/browser_context.h
+++ b/content/public/browser/browser_context.h
@@ -42,6 +42,7 @@ class ResourceContext;
 class SiteInstance;
 class StoragePartition;
 class SSLHostStateDelegate;
+class ZoomLevelPrefsDelegate;
 
 // This class holds the context needed for a browsing session.
 // It lives on the UI thread. All these methods must only be called on the UI
@@ -107,8 +108,19 @@ class CONTENT_EXPORT BrowserContext : public base::SupportsUserData {
   // across the next restart.
   static void SaveSessionState(BrowserContext* browser_context);
 
+  // Changes the default zoom level for all current storage partitions.
+  static void SetDefaultZoomLevel(BrowserContext* browser_context,
+                                  double level);
+
   virtual ~BrowserContext();
 
+  // Returns the default zoom level.
+  virtual double GetDefaultZoomLevel() const;
+
+  // Returns a delegate used to persist zoom level preference, or NULL if
+  // zoom levels are not persisted. The caller takes ownership of the delegate.

[awong, 2014/08/12 21:07:06]

This comment doesn't give me enough info to understand why we'd want to call
this, or why one would override the default. Can we expand a bit?

[wjmaclean, 2014/08/13 17:16:03]

Done.

+  virtual ZoomLevelPrefsDelegate* CreateZoomLevelPrefsDelegate();
+
   // Returns the path of the directory where this context's data is stored.
   virtual base::FilePath GetPath() const = 0;