[chromium] Add a method didChangeFormState to WebViewClient.

[chromium] Add a method didChangeFormState to WebViewClient.
https://bugs.webkit.org/show_bug.cgi?id=90563

Patch by Oli Lan <olilan@chromium.org> on 2012-07-05
Reviewed by Adam Barth.

This patch adds a new method didChangeFormState to WebViewClient,
and calls it from ChromeClientImpl::formStateDidChange with the changed node.

This new method can be used for example by the Android port to update the browser's
IME when the state of the currently focused text node has changed. To facilitate this
usage, a focused() method has been added to WebNode.

A new test has been added to WebViewTest. This test checks that didChangeFormState
is called when an input's value is changed, and also checks that WebNode::focused() returns
the correct value for the provided node, in both the focused and non-focused cases.

* public/WebNode.h:
* public/WebViewClient.h:
(WebKit::WebViewClient::didChangeFormState):
* src/ChromeClientImpl.cpp:
(WebKit::ChromeClientImpl::formStateDidChange):
* src/WebNode.cpp:
(WebKit::WebNode::focused):
(WebKit):
* tests/WebViewTest.cpp:
(FormChangeWebViewClient):
(WebKit::FormChangeWebViewClient::didChangeFormState):
(WebKit::FormChangeWebViewClient::reset):
(WebKit::FormChangeWebViewClient::called):
(WebKit::FormChangeWebViewClient::focused):
(WebKit):
(WebKit::TEST_F):
* tests/data/input_field_set_value_while_focused.html: Added.
* tests/data/input_field_set_value_while_not_focused.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@121904 268f45cc-cd09-0410-ab3c-d52691b4dbfc