Stop aggregating texture/buffer access objects in GrFragmentProcessor parents.

src/gpu/vk/GrVkGpuCommandBuffer.cpp

Index: src/gpu/vk/GrVkGpuCommandBuffer.cpp
diff --git a/src/gpu/vk/GrVkGpuCommandBuffer.cpp b/src/gpu/vk/GrVkGpuCommandBuffer.cpp
index a5840699b88dbafdc62b9109bdbc36e6dae89294..419e1b9f2cdc95bc46964418d9763bf13e20d883 100644
--- a/src/gpu/vk/GrVkGpuCommandBuffer.cpp
+++ b/src/gpu/vk/GrVkGpuCommandBuffer.cpp
@@ -395,8 +395,9 @@ void GrVkGpuCommandBuffer::onDraw(const GrPipeline& pipeline,
     SkASSERT(renderPass);
 
     prepare_sampled_images(primProc, fGpu);
-    for (int i = 0; i < pipeline.numFragmentProcessors(); ++i) {
-        prepare_sampled_images(pipeline.getFragmentProcessor(i), fGpu);
+    GrFragmentProcessor::Iter iter(pipeline);
+    while (const GrFragmentProcessor* fp = iter.next()) {
+        prepare_sampled_images(*fp, fGpu);
     }
     prepare_sampled_images(pipeline.getXferProcessor(), fGpu);