Implement WebViewDatabase's hasFormData API for chromium based webview.

components/autofill/browser/webdata/autofill_webdata.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_H_
 #define COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 23 matching lines @@
   // Initiates the request for a vector of values which have been entered in
   // form input fields named |name|.  The method OnWebDataServiceRequestDone of
   // |consumer| gets called back when the request is finished, with the vector
   // included in the argument |result|.
   virtual WebDataServiceBase::Handle GetFormValuesForElementName(
       const base::string16& name,
       const base::string16& prefix,
       int limit,
       WebDataServiceConsumer* consumer) = 0;
 
+  // Checks if there are any form elements in the database.
+  virtual WebDataServiceBase::Handle HasFormElements(
+      WebDataServiceConsumer* consumer) = 0;
+
   // Removes form elements recorded for Autocomplete from the database.
   virtual void RemoveFormElementsAddedBetween(
       const base::Time& delete_begin, const base::Time& delete_end) = 0;
 
   virtual void RemoveExpiredFormElements() = 0;
   virtual void RemoveFormValueForElementName(const base::string16& name,
                                              const base::string16& value) = 0;
 
   // Schedules a task to add an Autofill profile to the web database.
   virtual void AddAutofillProfile(const AutofillProfile& profile) = 0;
@@ skipping 30 matching lines @@
       WebDataServiceConsumer* consumer) = 0;
 
   // Removes Autofill records from the database.
   virtual void RemoveAutofillDataModifiedBetween(
       const base::Time& delete_begin, const base::Time& delete_end) = 0;
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_H_