Add Autofill preview support for <select> input fields

Add Autofill preview support for <select> input fields

Since changing the text in display of <select> will inevitably change the selectedIndex of the options, a workaround is introduced for this case. In the workaround,
it saves a copy of the original selected option and recovers this value once autofill preview is done. 

BUG=58719
R=dhollowa@chromium.org, isherman@chromium.org, jhawkins@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=259902

[James Hawkins, 2014-01-14 17:11:19]

Was support added for previewing a select element value without revealing the
preview to the page?  If so please provide some links to CLs or codesearch or
what have you pointing it out.

[ziran.sun, 2014-01-14 19:15:05]

On 2014/01/14 17:11:19, James Hawkins wrote:
> Was support added for previewing a select element value without revealing the
> preview to the page?  If so please provide some links to CLs or codesearch or
> what have you pointing it out.

It only previews the option that corresponds the "hovered over" suggestion in
the 
input field that double clicked.
For example, with the form.html file attached in the bug link, when "First Name"
is 
double clicked, a few suggestions for the names pop up, if we hover over one of
the
names in the popup list, say "Alice", if Alice is from state "CA", then CA is
shown
in the State <select> with yellow background, no other states are shown on the
screen. 

I checked again on the bug descriptions, I wonder if I have missed some points
here. Does the issue
mean - double click on the input field, without "hovering" happens, the <select>
will pop
up a full list of State options? This doesn't seem making sense to me. But do
please let me know 
if I missed anything here.  Thanks!

[Ilya Sherman, 2014-02-08 01:36:48]

On 2014/01/14 17:11:19, James Hawkins wrote:
> Was support added for previewing a select element value without revealing the
> preview to the page?  If so please provide some links to CLs or codesearch or
> what have you pointing it out.

Ziran is currently working on this in https://codereview.chromium.org/138433002/

[Ilya Sherman, 2014-02-08 01:40:41]

https://codereview.chromium.org/136793007/diff/1/chrome/renderer/autofill/for...
File chrome/renderer/autofill/form_autofill_browsertest.cc (right):

https://codereview.chromium.org/136793007/diff/1/chrome/renderer/autofill/for...
chrome/renderer/autofill/form_autofill_browsertest.cc:239: {
nit: Please keep all the curly braces as they were, per the Chromium style
guide.

https://codereview.chromium.org/136793007/diff/1/components/autofill/content/...
File components/autofill/content/renderer/form_autofill_util.cc (right):

https://codereview.chromium.org/136793007/diff/1/components/autofill/content/...
components/autofill/content/renderer/form_autofill_util.cc:596:
select_element.setOriginalValue(select_element.value());
This should not be necessary; the select element should keep track of this state
internally.

https://codereview.chromium.org/136793007/diff/1/components/autofill/content/...
components/autofill/content/renderer/form_autofill_util.cc:1067: // Only text
input, textarea and Select elements can be previewed.
nit: "Select" -> "select"

https://codereview.chromium.org/136793007/diff/1/components/autofill/content/...
components/autofill/content/renderer/form_autofill_util.cc:1119:
control_element.setAutofilled(false);
There's no need for handling the case where is_initiating_node is set to true,
because it's impossible to initiate Autofill from a <select> element.

https://codereview.chromium.org/136793007/diff/1/components/autofill/content/...
components/autofill/content/renderer/form_autofill_util.cc:1124:
select_element.setValue(WebString(select_element.originalValue()));
This should not be necessary; the <select> element should keep track of this
state internally.

[ziran.sun, 2014-02-28 15:52:58]

Code updated and addressed all the review comments. Please review. Thanks!

[Ilya Sherman, 2014-02-28 21:35:09]

LGTM, thanks.  (Though will need to wait for the Blink changes to land, of
course.)

[ziran.sun, 2014-03-27 11:47:36]

The CQ bit was checked by ziran.sun@samsung.com

[commit-bot: I haz the power, 2014-03-27 11:47:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ziran.sun@samsung.com/136793007/160001

[commit-bot: I haz the power, 2014-03-27 16:18:23]

Change committed as 259902