Merge CWVWebsiteDataStore into CWVWebViewConfiguration.

ios/web_view/public/cwv_web_view_configuration.h

Index: ios/web_view/public/cwv_web_view_configuration.h
diff --git a/ios/web_view/public/cwv_web_view_configuration.h b/ios/web_view/public/cwv_web_view_configuration.h
index aa4b96f0083de2d401bd49cf8662327bcbb28653..a2a7489b3c4cfe52c9aecddae946bd731bdc8f4d 100644
--- a/ios/web_view/public/cwv_web_view_configuration.h
+++ b/ios/web_view/public/cwv_web_view_configuration.h
@@ -12,9 +12,17 @@
 // Configuration used for creation of a CWVWebView.
 @interface CWVWebViewConfiguration : NSObject<NSCopying>
 
-// Data store defining persistance of website data. Default is
-// [CWVWebsiteDataStore defaultDataStore].
-@property(nonatomic, strong, nonnull) CWVWebsiteDataStore* websiteDataStore;
+// Configuration with persistent data store which stores all data on disk.
++ (instancetype)defaultConfiguration;
+
+// Configuration with ephemeral data store that neven stores data on disk.
++ (instancetype)incognitoConfiguration;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+// YES if it is a configuration with persistent data store which stores all data
+// on disk.
+@property(readonly, getter=isPersistent) BOOL persistent;
 
 @end