Refactor ResourcePool::AcquireResource() and add test.

cc/resources/resource_pool_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/resource_pool.h"
 
 #include <stddef.h>
 
 #include "base/run_loop.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/resources/resource_util.h"
 #include "cc/resources/scoped_resource.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_output_surface_client.h"
 #include "cc/test/fake_resource_provider.h"
 #include "cc/test/test_shared_bitmap_manager.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
-namespace {
 
 class ResourcePoolTest : public testing::Test {
  public:
   void SetUp() override {
     output_surface_ = FakeOutputSurface::CreateDelegating3d();
     ASSERT_TRUE(output_surface_->BindToClient(&output_surface_client_));
     shared_bitmap_manager_.reset(new TestSharedBitmapManager());
     resource_provider_ = FakeResourceProvider::Create(
         output_surface_.get(), shared_bitmap_manager_.get());
     task_runner_ = base::ThreadTaskRunnerHandle::Get();
@@ skipping 272 matching lines @@
   // content ID and that it has the expected invalidated rect.
   gfx::Rect total_invalidated_rect;
   reacquired_resource = resource_pool_->TryAcquireResourceForPartialRaster(
       content_ids[2], second_invalidated_rect, content_ids[1],
       &total_invalidated_rect);
   EXPECT_EQ(resource, reacquired_resource);
   EXPECT_EQ(expected_total_invalidated_rect, total_invalidated_rect);
   resource_pool_->ReleaseResource(reacquired_resource);
 }
 
-}  // namespace
+TEST_F(ResourcePoolTest, ReuseResource) {
+  ResourceFormat format = RGBA_8888;
+  gfx::ColorSpace color_space = gfx::ColorSpace::CreateSRGB();
+
+  // Create unused resources with sizes close to 100, 100.
+  resource_pool_->ReleaseResource(
+      resource_pool_->CreateResource(gfx::Size(99, 100), format, color_space));
+  resource_pool_->ReleaseResource(
+      resource_pool_->CreateResource(gfx::Size(99, 99), format, color_space));
+  resource_pool_->ReleaseResource(
+      resource_pool_->CreateResource(gfx::Size(100, 99), format, color_space));
+  resource_pool_->ReleaseResource(
+      resource_pool_->CreateResource(gfx::Size(101, 101), format, color_space));
+  resource_pool_->CheckBusyResources();
+
+  gfx::Size size(100, 100);
+  Resource* resource = resource_pool_->ReuseResource(size, format, color_space);
+  EXPECT_EQ(nullptr, resource);
+  size = gfx::Size(100, 99);
+  resource = resource_pool_->ReuseResource(size, format, color_space);
+  EXPECT_NE(nullptr, resource);
+  ASSERT_EQ(nullptr, resource_pool_->ReuseResource(size, format, color_space));
+  resource_pool_->ReleaseResource(resource);
+}
+
 }  // namespace cc