Simplify adding attributes to GrGeometryProcessor

src/gpu/GrGeometryProcessor.h

Index: src/gpu/GrGeometryProcessor.h
diff --git a/src/gpu/GrGeometryProcessor.h b/src/gpu/GrGeometryProcessor.h
index 1dbf1539a22bbb86d31bd45ad964d47ab87b15fa..ebb48fc4668032b26daf69a635f39978d25dd6b8 100644
--- a/src/gpu/GrGeometryProcessor.h
+++ b/src/gpu/GrGeometryProcessor.h
@@ -53,9 +53,10 @@ protected:
      * The processor key should reflect the vertex attributes, or there lack thereof in the
      * GrGeometryProcessor.
      */
-    const Attribute& addVertexAttrib(const Attribute& attribute) {

[bsalomon, 2016/08/17 15:59:01]

This is the real change. Everything else is changing the callers (and removing
default Attribute cons arg value in GrPrimitiveProcessor.h)

-        fVertexStride += attribute.fOffset;
-        fAttribs.push_back(attribute);
+    const Attribute& addVertexAttrib(const char* name, GrVertexAttribType type,
+                                     GrSLPrecision precision = kDefault_GrSLPrecision) {
+        fAttribs.emplace_back(name, type, precision);
+        fVertexStride += fAttribs.back().fOffset;
         return fAttribs.back();
     }