Begin instanced rendering for simple shapes

src/gpu/GrDrawTarget.cpp

Index: src/gpu/GrDrawTarget.cpp
diff --git a/src/gpu/GrDrawTarget.cpp b/src/gpu/GrDrawTarget.cpp
index 7213a92152af7d1efca0a48c65e815074a38a9a1..bd3caf5e44cf8d8fe6d239df2def11bd3c3b72e9 100644
--- a/src/gpu/GrDrawTarget.cpp
+++ b/src/gpu/GrDrawTarget.cpp
@@ -32,6 +32,8 @@
 #include "batches/GrRectBatchFactory.h"
 #include "batches/GrStencilPathBatch.h"
 
+#include "instanced/InstancedRendering.h"
+
 ////////////////////////////////////////////////////////////////////////////////
 
 // Experimentally we have found that most batching occurs within the first 10 comparisons.
@@ -44,7 +46,8 @@ GrDrawTarget::GrDrawTarget(GrRenderTarget* rt, GrGpu* gpu, GrResourceProvider* r
     , fResourceProvider(resourceProvider)
     , fAuditTrail(auditTrail)
     , fFlags(0)
-    , fRenderTarget(rt) {
+    , fRenderTarget(rt)
+    , fInstancedRendering(fGpu->createInstancedRenderingIfSupported()) {
     // TODO: Stop extracting the context (currently needed by GrClipMaskManager)
     fContext = fGpu->getContext();
 
@@ -204,6 +207,10 @@ void GrDrawTarget::prepareBatches(GrBatchFlushState* flushState) {
             fBatches[i]->prepare(flushState);
         }
     }
+
+    if (fInstancedRendering) {
+        fInstancedRendering->beginFlush(flushState->resourceProvider());
+    }
 }
 
 void GrDrawTarget::drawBatches(GrBatchFlushState* flushState) {
@@ -231,6 +238,9 @@ void GrDrawTarget::drawBatches(GrBatchFlushState* flushState) {
 
 void GrDrawTarget::reset() {
     fBatches.reset();
+    if (fInstancedRendering) {
+        fInstancedRendering->endFlush();
+    }
 }
 
 void GrDrawTarget::drawBatch(const GrPipelineBuilder& pipelineBuilder,