Check for some potential subheap allocation failures.

tests/VkHeapTests.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // This is a GPU-backend specific test. It relies on static intializers to work
 
 #include "SkTypes.h"
@@ skipping 137 matching lines @@
     REPORTER_ASSERT(reporter, heap.alloc(22 * 1024, kAlignment, kHeapIndex, &alloc2));
     REPORTER_ASSERT(reporter, heap.allocSize() == 128 * 1024 && heap.usedSize() == 107 * 1024);
     heap.free(alloc1);
     REPORTER_ASSERT(reporter, heap.allocSize() == 128 * 1024 && heap.usedSize() == 102 * 1024);
     heap.free(alloc0);
     REPORTER_ASSERT(reporter, heap.allocSize() == 128 * 1024 && heap.usedSize() == 62 * 1024);
     heap.free(alloc2);
     REPORTER_ASSERT(reporter, heap.allocSize() == 128 * 1024 && heap.usedSize() == 40 * 1024);
     heap.free(alloc3);
     REPORTER_ASSERT(reporter, heap.allocSize() == 128 * 1024 && heap.usedSize() == 0 * 1024);
+    // heap should not grow here (allocating more than subheap size)
+    REPORTER_ASSERT(reporter, heap.alloc(128 * 1024, kAlignment, kHeapIndex, &alloc0));
+    REPORTER_ASSERT(reporter, 0 == alloc0.fSize);
+    REPORTER_ASSERT(reporter, heap.allocSize() == 128 * 1024 && heap.usedSize() == 0 * 1024);
+    heap.free(alloc0);
 }
 
 void singlealloc_test(skiatest::Reporter* reporter, GrContext* context) {
     GrVkGpu* gpu = static_cast<GrVkGpu*>(context->getGpu());
 
     // heap index doesn't matter, we're just testing the allocation algorithm so we'll use 0
     GrVkHeap heap(gpu, GrVkHeap::kSingleAlloc_Strategy, 64 * 1024);
     GrVkAlloc alloc0, alloc1, alloc2, alloc3;
     const VkDeviceSize kAlignment = 64;
     const uint32_t kHeapIndex = 0;
@@ skipping 31 matching lines @@
     REPORTER_ASSERT(reporter, heap.allocSize() == 112 * 1024 && heap.usedSize() == 0 * 1024);
 }
 
 DEF_GPUTEST_FOR_VULKAN_CONTEXT(VkHeapTests, reporter, ctxInfo) {
     subheap_test(reporter, ctxInfo.grContext());
     suballoc_test(reporter, ctxInfo.grContext());
     singlealloc_test(reporter, ctxInfo.grContext());
 }
 
 #endif