Simplifies filter preparation by incorporating SVG filter resolution and
CSS filter box transformation into the filter absolute transform.

Removes secondary clamping in RenderSVGFilterBuilder which isn't
necessary as the size of intermediate buffers will never exceed the size
of the filter region for SVG.

Changes source image rectangles of filters to be integer rectangles to
ensure all source buffers share the same pixel alignment as the
destination.

Fixes region, source and crop rectangle calculations for
CSS filter applications which were sometimes not done in
the correct coordinate space.

Fixes double application of scale in feTurbulence.

BUG=333014,335069,335282,336357

Review URL: https://codereview.chromium.org/134213002

git-svn-id: svn://svn.chromium.org/blink/trunk@165468 bbb929c8-8fbe-4397-9dbb-9b2b20218538