Fix incorrect comment about XMLHttpRequest::handleDidCancel()

handleDidCancel() doesn't handle m_loader->cancel() in internalAbort().
It's for handling cancellation coming from other components.

BUG=none

Review URL: https://codereview.chromium.org/467593002

git-svn-id: svn://svn.chromium.org/blink/trunk@180078 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove unknown preferences errors in layout tests

This change removes all the following errors

CONSOLE MESSAGE: Invalid name for preference: foobar

by removing 2 tests that were the only users of some invalid
preference and removing some unneeded override in the css3/filters/
directory. It also adds a presubmit hooks so that we don't let
more errors creep into our tests.

Review URL: https://codereview.chromium.org/457893003

git-svn-id: svn://svn.chromium.org/blink/trunk@180080 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[DevTools] Changed checks in InspectorConsoleWindow::autogenerateMetadata

Removed part of the check related to the type of agent. This test was important when the engine used another JS engine.

ScriptState no longer participates in check. And now only used to obtain the ID of context.

The method createScriptCallStackForConsole now uses a method call createScriptCallStack forming a stack which is able to receive an empty stack and not adds a fake frame.

NOTRY=true

Review URL: https://codereview.chromium.org/460743003

git-svn-id: svn://svn.chromium.org/blink/trunk@180081 bbb929c8-8fbe-4397-9dbb-9b2b20218538