Make execCommand("insertImage", false, "") not add a src attribute

Make execCommand("insertImage", false, "") not add a src attribute

This matches IE's behavior, and most importantly will preserve the
behavior of the 1-argument execCommand("insertImage") when the default
value changes from null to "", needed to match the spec.

A spec bug has been filed asking for the same change:
https://www.w3.org/Bugs/Public/show_bug.cgi?id=27552

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=186936

[philipj_slow, 2014-12-10 12:26:20]

philipj@opera.com changed reviewers:
+ yutak@chromium.org

[philipj_slow, 2014-12-10 12:26:21]

PTAL, this will fix the second test failure of
https://codereview.chromium.org/751553005/

[Yuta Kitamura, 2014-12-11 02:35:50]

yutak@chromium.org changed reviewers:
+ yosin@chromium.org

[Yuta Kitamura, 2014-12-11 02:35:50]

lgtm with nits

https://codereview.chromium.org/788153003/diff/1/LayoutTests/editing/execComm...
File LayoutTests/editing/execCommand/insertImage-src.html (right):

https://codereview.chromium.org/788153003/diff/1/LayoutTests/editing/execComm...
LayoutTests/editing/execCommand/insertImage-src.html:12: test(function() {
We usually apply Blink's (C++) coding style in JavaScript in
layout tests, too, i.e. 4-space indent, no abbreviation in
variable names, etc.

[philipj_slow, 2014-12-11 08:20:38]

https://codereview.chromium.org/788153003/diff/1/LayoutTests/editing/execComm...
File LayoutTests/editing/execCommand/insertImage-src.html (right):

https://codereview.chromium.org/788153003/diff/1/LayoutTests/editing/execComm...
LayoutTests/editing/execCommand/insertImage-src.html:12: test(function() {
On 2014/12/11 02:35:50, Yuta Kitamura wrote:
> We usually apply Blink's (C++) coding style in JavaScript in
> layout tests, too, i.e. 4-space indent, no abbreviation in
> variable names, etc.

http://www.chromium.org/blink/coding-style/layout-test-style-guidelines actually
explicitly allows both styles of indentation and braces now, but you're right,
most other tests in this directory have four spaces of indentation, so I'll
adapt to that and expand the variable name.

[philipj_slow, 2014-12-11 08:26:10]

tweak test style

[philipj_slow, 2014-12-11 08:49:40]

The CQ bit was checked by philipj@opera.com

[commit-bot: I haz the power, 2014-12-11 08:50:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/788153003/20001

[commit-bot: I haz the power, 2014-12-11 10:34:01]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=186936