Do not apply hairline optimization for paths if nv_path_rendering is used

Do not convert thin, non-hairline paths to hairline paths if
nv_path_rendering is used.

The current nv_path_rendering implementation does not render
hairlines. Rendering the hairlines with normal renderers cause
unneccessary gl program changes, which is quite slow.

Changes the behavior of non-nv_path_rendering paths to always perform
the optimization if the shape ends up being painted by the
path-drawing code (GrContext::drawPathInternal). Previously the
optimization was applied only when callgraph started with
SkCanvas::drawPath. This changes drawlooper_msaa4, dashing3_msaa4 and
dashing3_gpu

R=bsalomon@google.com

Author: kkinnunen@nvidia.com

Review URL: https://codereview.chromium.org/38573007

git-svn-id: http://skia.googlecode.com/svn/trunk/src@12185 2bbb7eff-a529-9590-31e7-b0007b416f81
12 files changed