handle null vertex or index buffers in batch

src/gpu/GrOvalRenderer.cpp

Index: src/gpu/GrOvalRenderer.cpp
diff --git a/src/gpu/GrOvalRenderer.cpp b/src/gpu/GrOvalRenderer.cpp
index fc8c18410cad0f76d20ed4226a2b8ab2317f3880..20ae77cb5244a258bec1de34730772d4f2f2d33f 100644
--- a/src/gpu/GrOvalRenderer.cpp
+++ b/src/gpu/GrOvalRenderer.cpp
@@ -762,6 +762,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices || !batchTarget->quadIndexBuffer()) {
+            SkDebugf("Could not allocate buffers\n");
+            return;
+        }
+
         CircleVertex* verts = reinterpret_cast<CircleVertex*>(vertices);
 
         for (int i = 0; i < instanceCount; i++) {
@@ -1012,6 +1017,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices || !batchTarget->quadIndexBuffer()) {
+            SkDebugf("Could not allocate buffers\n");
+            return;
+        }
+
         EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(vertices);
 
         for (int i = 0; i < instanceCount; i++) {
@@ -1303,6 +1313,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices || !batchTarget->quadIndexBuffer()) {
+            SkDebugf("Could not allocate buffers\n");
+            return;
+        }
+
         DIEllipseVertex* verts = reinterpret_cast<DIEllipseVertex*>(vertices);
 
         for (int i = 0; i < instanceCount; i++) {
@@ -1692,6 +1707,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+
         CircleVertex* verts = reinterpret_cast<CircleVertex*>(vertices);
 
         for (int i = 0; i < instanceCount; i++) {
@@ -1896,6 +1916,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+
         EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(vertices);
 
         for (int i = 0; i < instanceCount; i++) {