Sync the getComputedStyle() IDL with the spec

http://dev.w3.org/csswg/cssom/#extensions-to-the-window-interface

Firefox and IE already throw exceptions for getComputedStyle(),
getComputedStyle(null), getComputedStyle(undefined) and
getComputedStyle(document);

Previously, getComputedStyle() would fail the ASSERT(elt) in
LocalDOMWindow::getComputedStyle().

Review URL: https://codereview.chromium.org/765123002

git-svn-id: svn://svn.chromium.org/blink/trunk@186258 bbb929c8-8fbe-4397-9dbb-9b2b20218538
4 files changed
tree: 757dd8c0c274cec918231b72c42fd83fd74c8e6c
  1. third_party/