DevTools: Keep DOM breakpoint context menu actions and UI in sync

BUG=417184

Review URL: https://codereview.chromium.org/621733002

git-svn-id: svn://svn.chromium.org/blink/trunk@183054 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Credential Manager: Remove WebString from WebCredentialManagerError.

The enum gives enough detail; we don't need an additional string to be
created and passed around.

BUG=400674

Review URL: https://codereview.chromium.org/618723002

git-svn-id: svn://svn.chromium.org/blink/trunk@183056 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: hide transiently enabled experiments on the settings screen

We don't allow to disable transiently enabled experiments so they shouldn't be present on the settings screen.

BUG=None

Review URL: https://codereview.chromium.org/619883002

git-svn-id: svn://svn.chromium.org/blink/trunk@183057 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [CSS] support different cssrule types in InspectorStyleSheet

The patch adds flattenning and source data collecting of the following
CSSRules:
- charset rule
- page rule
- font-face rule
- viewport rule

The charset rule was lacking source data generation, so the bison grammer
had to be changed in order to support it.

BUG=417778
R=apavlov

Review URL: https://codereview.chromium.org/606023002

git-svn-id: svn://svn.chromium.org/blink/trunk@183058 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[Invalidation Tracking] add TraceEvents for setNeedsStyleRecalc.

Depends on http://crrev.com/547823002 .

This CL introduces a devtools.timeline TraceEvent for Node::setNeedsStyleRecalc.

The TraceEvent is going to be used in devtools to track style invalidation reasons.
Please see the bug for more info.

BUG=410701

Review URL: https://codereview.chromium.org/600733005

git-svn-id: svn://svn.chromium.org/blink/trunk@183059 bbb929c8-8fbe-4397-9dbb-9b2b20218538