IDL compiler: Remove redundant UseCounter calls from overloaded methods

UseCounter calls (UseCounter::count and UseCounter::countDeprecation)
for [MeasureAs] and [DeprecatedAs] are in the callback.

However, for overloaded methods these were incorrectly also placed in
the overload resolution method.

Only one use:
CanvasRenderingContext.webkitPutImageDataHD
...which has:
[DeprecateAs=PrefixedPutImageDataHD]

Longer-term, as with other extended attributes, we'll want to put these
in the individual overloaded function if these differ, so we can count
different overloaded methods differently.

R=haraken

Review URL: https://codereview.chromium.org/156123003

git-svn-id: svn://svn.chromium.org/blink/trunk@166588 bbb929c8-8fbe-4397-9dbb-9b2b20218538