Move DrawInfo out from GrDrawTarget and rename to GrVertices.

Review URL: https://codereview.chromium.org/1124733004
diff --git a/src/gpu/GrBatch.cpp b/src/gpu/GrBatch.cpp
index 38ab142..7d1c0ae 100644
--- a/src/gpu/GrBatch.cpp
+++ b/src/gpu/GrBatch.cpp
@@ -69,7 +69,7 @@
     size_t ibSize = indexBuffer->gpuMemorySize();
     fMaxInstancesPerDraw = static_cast<int>(ibSize / (sizeof(uint16_t) * indicesPerInstance));
 
-    fDrawInfo.initInstanced(primType, vertexBuffer, indexBuffer,
+    fVertices.initInstanced(primType, vertexBuffer, indexBuffer,
         firstVertex, verticesPerInstance, indicesPerInstance, &fInstancesRemaining,
         fMaxInstancesPerDraw);
     SkASSERT(fMaxInstancesPerDraw > 0);