Remove multiple inheritance support from the bindings generator

Remove multiple inheritance support from the bindings generator as this
is no longer supported in Web IDL and it makes the generator more
complex than it needs to be.

Multiple inheritance support is no longer needed now that our SVG
interfaces have been updated to use Web IDL 'implements' statements
instead.

BUG=256968

Review URL: https://chromiumcodereview.appspot.com/18636002

git-svn-id: svn://svn.chromium.org/blink/trunk@153496 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Enable custom "this" value in V8 IDL callbacks

Add IDL extended attribute "CallbackThisArgument" to be used on callback
method parameter definitions to indicate the value of the "this" object.

Relevant spec:
http://www.w3.org/TR/WebIDL/#dfn-callback-this-value
"By default, the object itself is used as the callback this value,
however this may be overridden by other specifications."

BUG=256961

Review URL: https://chromiumcodereview.appspot.com/18614004

git-svn-id: svn://svn.chromium.org/blink/trunk@153497 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [FlameChart] Users would like to jump to the source when they click on a bar.

It was possible only when the function had url.
Now when v8 publishes scriptId for CpuProfileNode we could jump to the source
even if the function has no resource name (eval).

BUG=none
TEST=none
R=yurys@chromium.org

Review URL: https://codereview.chromium.org/18631002

git-svn-id: svn://svn.chromium.org/blink/trunk@153499 bbb929c8-8fbe-4397-9dbb-9b2b20218538