FrameView::updateWidgets() can be made simpler

The widget updating code was all done in terms of RenderObject* and then
checked for isEmbeddedObject() but it turns out it only ever interacts
with RenderEmbeddedObjects so we can tighten the types and simplify the
code a whole bunch like removing all the manual ref count management
and merging the function into the loop now that it's much simpler.

Review URL: https://codereview.chromium.org/109943004

git-svn-id: svn://svn.chromium.org/blink/trunk@163490 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[XHR] remove now-unnecessary RaisesException attributes.

A handful of getters and methods now follow the spec and no longer
throw: synchronize their signatures and underlying IDL to reflect that
by removing [RaisesException] use.

R=tyoshino@chromium.org
BUG=

Review URL: https://codereview.chromium.org/108573002

git-svn-id: svn://svn.chromium.org/blink/trunk@163491 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove uses of deprecated toWebCoreStringWithUndefinedOrNullCheck(v8::Handle<v8::Value>)

Remove uses of deprecated toWebCoreStringWithUndefinedOrNullCheck(v8::Handle<v8::Value>) and
use V8TRYCATCH_FOR_V8STRINGRESOURCE*() macros instead so that we return early if an exception
is thrown by v8::String::ToString().

R=haraken

Review URL: https://codereview.chromium.org/110663003

git-svn-id: svn://svn.chromium.org/blink/trunk@163492 bbb929c8-8fbe-4397-9dbb-9b2b20218538