handle null vertex or index buffers in batch

src/gpu/GrAARectRenderer.cpp

Index: src/gpu/GrAARectRenderer.cpp
diff --git a/src/gpu/GrAARectRenderer.cpp b/src/gpu/GrAARectRenderer.cpp
index 7c34c25abd405dfd64a7c51ab61dd3e54627174a..6affc927ac6de376cd25c9f8c5bbc8b2fa97eb5b 100644
--- a/src/gpu/GrAARectRenderer.cpp
+++ b/src/gpu/GrAARectRenderer.cpp
@@ -134,6 +134,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+
         for (int i = 0; i < instanceCount; i++) {
             const Geometry& args = fGeoData[i];
             this->generateAAFillRectGeometry(vertices,
@@ -445,13 +450,18 @@ void GrAARectRenderer::geometryFillAARect(GrDrawTarget* target,
                                           const SkMatrix& viewMatrix,
                                           const SkRect& rect,
                                           const SkRect& devRect) {
-    if (NULL == fAAFillRectIndexBuffer) {
+    if (!fAAFillRectIndexBuffer) {
         fAAFillRectIndexBuffer = fGpu->createInstancedIndexBuffer(gFillAARectIdx,
                                                                   kIndicesPerAAFillRect,
                                                                   kNumAAFillRectsInIndexBuffer,
                                                                   kVertsPerAAFillRect);
     }
 
+    if (!fAAFillRectIndexBuffer) {
+        SkDebugf("Unable to create index buffer\n");
+        return;
+    }
+
     AAFillRectBatch::Geometry geometry;
     geometry.fRect = rect;
     geometry.fViewMatrix = viewMatrix;
@@ -623,6 +633,11 @@ public:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+
         for (int i = 0; i < instanceCount; i++) {
             const Geometry& args = fGeoData[i];
             this->generateAAStrokeRectGeometry(vertices,
@@ -846,7 +861,7 @@ void GrAARectRenderer::geometryStrokeAARect(GrDrawTarget* target,
                                             const SkRect& devInside,
                                             bool miterStroke) {
     GrIndexBuffer* indexBuffer = this->aaStrokeRectIndexBuffer(miterStroke);
-    if (NULL == indexBuffer) {
+    if (!indexBuffer) {
         SkDebugf("Failed to create index buffer!\n");
         return;
     }