IDL compiler: [DeprecateAs] for [InitializedByEventConstructor] attributes

1 use:
Source/core/events/KeyboardEvent.idl
[ImplementedAs=location, DeprecateAs=KeyboardEventKeyLocation, InitializedByEventConstructor] readonly attribute unsigned long keyLocation;

Also minor cleanup of Perl CG (fix dead code + simplify).

BUG=239771

Review URL: https://codereview.chromium.org/109823005

git-svn-id: svn://svn.chromium.org/blink/trunk@163496 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations CSS: Avoid transitioning on style changes made by the StyleAdjuster

Previously the StyleAdjuster made changes to the RenderStyle after
animated properties were applied. While comparing property values
for the purpose of starting new transitions we would compare an old
adjusted RenderStyle with a new not-adjusted RenderStyle. This
meant that there were certain cases, such as the implicit margin on
some input elements, that would trigger false transitions.

This change causes the Web Animations engine to fail some layer
related interpolation tests that were previously broken in the
legacy engine. 

BUG=325799

Review URL: https://codereview.chromium.org/109933004

git-svn-id: svn://svn.chromium.org/blink/trunk@163497 bbb929c8-8fbe-4397-9dbb-9b2b20218538