Add text field change handling for autofill preview in textarea element.

public/web/WebAutofillClient.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebAutofillClient_h
 #define WebAutofillClient_h
 
 namespace blink {
 
+class WebFormControlElement;
 class WebFormElement;
 class WebFrame;
 class WebInputElement;
 class WebKeyboardEvent;
 class WebNode;
 
 template <typename T> class WebVector;
 
 class WebAutofillClient {
 public:
     enum {
         MenuItemIDAutocompleteEntry = 0,
         MenuItemIDWarningMessage = -1,
         MenuItemIDPasswordEntry = -2,
         MenuItemIDSeparator = -3,
         MenuItemIDClearForm = -4,
         MenuItemIDAutofillOptions = -5,
         MenuItemIDDataListEntry = -6
     };
 
     // Informs the browser an interactive autocomplete has been requested.
     virtual void didRequestAutocomplete(WebFrame*, const WebFormElement&) { }
 
     // These methods are called when the users edits a text-field.
     virtual void textFieldDidEndEditing(const WebInputElement&) { }
-    virtual void textFieldDidChange(const WebInputElement&) { }
+    virtual void textFieldDidChange(const WebFormControlElement&) { }

[tkent, 2014/02/06 00:05:45]

Is the WebAutofillClient implementation in Chromium ready for this change?
If this CL is landed and the WebAutofillClient still implements the old
signature, the WebAutofillClient doesn't receive textFieldDidChange
notification.

[ziran.sun, 2014/02/06 10:32:17]

Yes. Check line 93
https://codereview.chromium.org/140093005/diff/1/components/autofill/content/...

I guess this CL needs to land together with the CL in the link? I've added you
as reviewer for above commit. Hope it's okay.

[tkent, 2014/02/07 06:04:09]

It's almost impossible to land a Chromium CL and a Blink CL at the same time
because of Blink roll delay.

The process should be:
1. Chromium: Remove OVERRIDE from textFieldDidChange(const WebInputElement&),
and add textFieldDidChange(const WebFormControlElement&) implementation without
OVERRIDE.
2. Blink: Land this CL
3. Wait until next Blink roll
4. Chromium: Remove textFieldDidChange(const WebInputElement&), and add OVERRIDE
to textFieldDidChange(const WebFormControlElement&)

     virtual void textFieldDidReceiveKeyDown(const WebInputElement&, const WebKeyboardEvent&) { }
     // This is called when a datalist indicator is clicked.
     virtual void openTextDataListChooser(const WebInputElement&) { }
 
     // Informs the client whether or not any subsequent text changes should be ignored.
     virtual void setIgnoreTextChanges(bool ignore) { }
 
     virtual void didAssociateFormControls(const WebVector<WebNode>&) { }
 
 protected:
     virtual ~WebAutofillClient() { }
 };
 
 } // namespace blink
 
 #endif