Start to propagate constness of GrPipelineBuilder up the stack

gm/convexpolyeffect.cpp

Index: gm/convexpolyeffect.cpp
diff --git a/gm/convexpolyeffect.cpp b/gm/convexpolyeffect.cpp
index b27f7c20393d6565503e40785de986c28fcefb6e..2c77bceb0ac43fe352e2776ffe8ba514d6f6dab8 100644
--- a/gm/convexpolyeffect.cpp
+++ b/gm/convexpolyeffect.cpp
@@ -195,7 +195,7 @@ protected:
 
                 SkAutoTUnref<GrBatch> batch(ConvexPolyTestBatch::Create(gp, geometry));
 
-                tt.target()->drawBatch(&pipelineBuilder, batch);
+                tt.target()->drawBatch(pipelineBuilder, batch);
 
                 x += SkScalarCeilToScalar(path->getBounds().width() + 10.f);
             }
@@ -244,7 +244,7 @@ protected:
 
                 SkAutoTUnref<GrBatch> batch(ConvexPolyTestBatch::Create(gp, geometry));
 
-                tt.target()->drawBatch(&pipelineBuilder, batch);
+                tt.target()->drawBatch(pipelineBuilder, batch);
 
                 x += SkScalarCeilToScalar(rect.width() + 10.f);
             }