Allow tabbing to anchors with explicit tabIndex even when tabsToLinks is disabled

With tabsToLinks setting enabled, browser focuses all links on pressing tab.
With it disabled, it does not focus any. This patch changes behavior when the
option is disabled so that links with explicit tabIndex are focusable. When
author has specified tabIndex, he most likely wants the element to be keyboard
accessible.

This option is by default enabled but only Mac exposes it in the settings so
it only affects Mac users who have changed default settings.

BUG=240678

Review URL: https://chromiumcodereview.appspot.com/15238002

git-svn-id: svn://svn.chromium.org/blink/trunk@157684 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[DevTools] NetworkPanel: fallback view doesn't respect line breaks.

Fallback resource view wraps long lines, but doesn't respect line breaks
and whitespaces.

So, even if resource is formatted, it will turn to mess.

BUG=

Review URL: https://chromiumcodereview.appspot.com/23809014

git-svn-id: svn://svn.chromium.org/blink/trunk@157685 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Declare extensionServer for generated devtools_extension_api.js

BUG=289034

Review URL: https://chromiumcodereview.appspot.com/23883012

git-svn-id: svn://svn.chromium.org/blink/trunk@157686 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[DevTools] NetworkPanel: add option to see/copy long WS frame messages.

WS frames are not wrapped anymore.

To see full message content user can hover massage and look at popup.
Also added context menu to copy message to clipboard.

BUG=286419

Review URL: https://chromiumcodereview.appspot.com/24090002

git-svn-id: svn://svn.chromium.org/blink/trunk@157688 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert "Rebaseline after Blink@157679"

This reverts commit 0e5612dec0a69868b85dc07bb4315a6af3bccafe.

These new baselines are not correct.  The bots are just missing some IDL
changes.

TBR=ch.dumez@sisa.samsung.com

Review URL: https://codereview.chromium.org/23533052

git-svn-id: svn://svn.chromium.org/blink/trunk@157689 bbb929c8-8fbe-4397-9dbb-9b2b20218538