Make GrVertexBatch objects hold their own draws during GrDrawTarget flush

src/gpu/GrBufferedDrawTarget.cpp

Index: src/gpu/GrBufferedDrawTarget.cpp
diff --git a/src/gpu/GrBufferedDrawTarget.cpp b/src/gpu/GrBufferedDrawTarget.cpp
index 36542a1127e93c1c69ddb504c6cb463a228fd709..a706bf39327a1e4ac24ffec8787cef5c1eb2b447 100644
--- a/src/gpu/GrBufferedDrawTarget.cpp
+++ b/src/gpu/GrBufferedDrawTarget.cpp
@@ -103,7 +103,7 @@ void GrBufferedDrawTarget::onReset() {
 }
 
 void GrBufferedDrawTarget::onFlush() {
-    fCommands->flush(this);
+    fCommands->flush(this->getGpu(), this->getContext()->resourceProvider());
     ++fDrawID;
 }