[WebSocket] Merge duplicated HTTP headers for devtools

The new WebSocket implementation receives HTTP headers on
the opening handshake from the browser process.
The headers may be duplicated, e.g. there are two "Foo" headers.
In order to show duplicated headers in devtools, this CL merges them
during storing them to HTTPHeaderMap.
This CL changes the existing WebSocket behavior as well.

R=tyoshino
BUG=310405

Review URL: https://codereview.chromium.org/130863002

git-svn-id: svn://svn.chromium.org/blink/trunk@165044 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update more svg classes to use OVERRIDE / FINAL when needed

Update more svg classes to use OVERRIDE / FINAL when needed. Those are
useful for error checking or performance when the compiler supports it.

These were found using the chromium style clang plugin.

R=pdr, schenney@chromium.org
BUG=333316

Review URL: https://codereview.chromium.org/137063005

git-svn-id: svn://svn.chromium.org/blink/trunk@165045 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Console object preview should not be lossless if it has accessors.

After expanding an accessor in the preview, the value may not be lossless
(e.g. a long truncated string), thus assume such preview not lossless as well.

BUG=261470
R=pfeldman

Review URL: https://codereview.chromium.org/137883002

git-svn-id: svn://svn.chromium.org/blink/trunk@165046 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update heap/ classes to use OVERRIDE / FINAL when needed

Update heap/ classes to use OVERRIDE / FINAL when needed. Those are
useful for error checking or performance when the compiler supports it.

These were found using the chromium style clang plugin.

R=haraken
BUG=333316

Review URL: https://codereview.chromium.org/137803004

git-svn-id: svn://svn.chromium.org/blink/trunk@165047 bbb929c8-8fbe-4397-9dbb-9b2b20218538
HTMLFormControlElement::didRecalcStyle doesn't need to use PostAttachCallbacks

Near as I can tell updateFromElement() can no longer cause the selection to
change so lets stop using PostAttachCallbacks. This leaves only
scheduleLayerUpdate and autofocus using post attach callbacks. A future patch
will move autofocus off it and then we can make PostAttachCallbacks specific
to the layer updating system (and hopefully remove that usage someday too).

Review URL: https://codereview.chromium.org/131153002

git-svn-id: svn://svn.chromium.org/blink/trunk@165048 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Regularize extended attributes on partial interfaces

This is cleanup CL, as part of implementing partial interfaces in the
Python IDL compiler.
Primarily it moves overall [RuntimeEnabled] extended attributes (and
[Conditional] and [PerContextEnabled]) to the partial interface itself,
rather than individual members, so:

[
　　RuntimeEnabled=FeatureName,
] partial interface Foo {
　　void a();
　　void b();
};

instead of:

partial interface Foo {
　　[RuntimeEnabled=FeatureName] void a();
　　[RuntimeEnabled=FeatureName] void b();
};

This is for consistency: these extended attributes can be applied
to the partial interface itself, which means they are applied to
all members, so we can switch it on or off with one line.

Currently some IDL files put this on the partial interface, while
others put it on all members; this makes it consistent and clarifies intent.

(We could remove all of these, simplifying merging a bit, at the cost
of putting these on all the individual member lines.)

Docs:
https://sites.google.com/a/chromium.org/dev/blink/webidl/blink-idl-extended-attributes#TOC-Partial-interfaces

No changes to generated code.

R=haraken

Review URL: https://codereview.chromium.org/130943004

git-svn-id: svn://svn.chromium.org/blink/trunk@165049 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make pause-on-exceptions toggle/tri-state button.

BUG=

Review URL: https://codereview.chromium.org/102003006

git-svn-id: svn://svn.chromium.org/blink/trunk@165051 bbb929c8-8fbe-4397-9dbb-9b2b20218538