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@12185 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLProgram.cpp b/src/gpu/gl/GrGLProgram.cpp
index accaf88..5b030fa 100644
--- a/src/gpu/gl/GrGLProgram.cpp
+++ b/src/gpu/gl/GrGLProgram.cpp
@@ -207,10 +207,10 @@
         coverage = 0;
     } else if (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) {
         color = 0xffffffff;
-        coverage = drawState.getCoverage();
+        coverage = drawState.getCoverageColor();
     } else {
         color = drawState.getColor();
-        coverage = drawState.getCoverage();
+        coverage = drawState.getCoverageColor();
     }
 
     this->setColor(drawState, color, sharedState);