Crash fix, submitting dialog forms.

The crash occurs when a form has method=dialog but no submit button and is then
submitted (e.g., via JavaScript, myform.submit()). This code path is only hit
when the experimental runtime feature "dialogElementEnabled" is enabled (e.g.,
content_shell does that).

BUG=346147
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/177093024

git-svn-id: svn://svn.chromium.org/blink/trunk@167910 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Make box-sizing model for ::before and ::after pseudos uniform with others.

R=yurys@chromium.org

Review URL: https://codereview.chromium.org/177003018

git-svn-id: svn://svn.chromium.org/blink/trunk@167911 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Add ability to show editor in drawer split view.

R=pfeldman

Review URL: https://codereview.chromium.org/172173005

git-svn-id: svn://svn.chromium.org/blink/trunk@167912 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Followup for r167903 fixing devtools extensions browser_tests

TBR=pfeldman

Review URL: https://codereview.chromium.org/181563002

git-svn-id: svn://svn.chromium.org/blink/trunk@167913 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Replace Apple styled spinner icon with Chromium one.

Drive-by: replace animated PNG files with a CSS animation.

R=yurys@chromium.org

Review URL: https://codereview.chromium.org/181433002

git-svn-id: svn://svn.chromium.org/blink/trunk@167914 bbb929c8-8fbe-4397-9dbb-9b2b20218538