Rename vars and functions from 'glslcaps'->'shadercaps'

Change-Id: I34d226d866dd4ba8e5f33f95cb8cbf01292f9314
Reviewed-on: https://skia-review.googlesource.com/5312
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 0e50bcc..2d79f9a 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -614,7 +614,7 @@
 
     fGLDomain.sampleTexture(fragBuilder,
                             args.fUniformHandler,
-                            args.fGLSLCaps,
+                            args.fShaderCaps,
                             domain,
                             args.fOutputColor,
                             SkString(cCoords),