Use V8TRYCATCH_FOR_V8STRINGRESOURCE() macro instead of toCoreStringWithUndefinedOrNullCheck()

Use V8TRYCATCH_FOR_V8STRINGRESOURCE() macro instead of toCoreStringWithUndefinedOrNullCheck()
when necessary. Namely, when an exception may be thrown, we should use the macro instead to
return early when the call to ToString() throws.

This patch also updates toCoreStringWithUndefinedOrNullCheck(v8::Handle<v8::Value>()) to
stop calling ToString(). This method can never throw and is thus now safe to use if the
caller wants to convert to WTF String only if the v8::Value contains a v8::String. This
utility method is used in the inspector code.

R=haraken, pfeldman
BUG=327338

Review URL: https://codereview.chromium.org/100963003

git-svn-id: svn://svn.chromium.org/blink/trunk@163873 bbb929c8-8fbe-4397-9dbb-9b2b20218538