gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/buffer_tracker_unittest.cc

Index: gpu/command_buffer/client/buffer_tracker_unittest.cc
diff --git a/gpu/command_buffer/client/buffer_tracker_unittest.cc b/gpu/command_buffer/client/buffer_tracker_unittest.cc
index a2988443c254d9da4eaa13c214ec422e9b6ee7ff..f6174c0802b3d9681d52a58e929173c33591e8b8 100644
--- a/gpu/command_buffer/client/buffer_tracker_unittest.cc
+++ b/gpu/command_buffer/client/buffer_tracker_unittest.cc
@@ -42,6 +42,11 @@ class MockClientCommandBufferImpl : public MockClientCommandBuffer {
   bool context_lost_;
 };
 
+namespace {
+void EmptyPoll() {
+}
+}
+
 class BufferTrackerTest : public testing::Test {
  protected:
   static const int32 kNumCommandEntries = 400;
@@ -53,7 +58,7 @@ class BufferTrackerTest : public testing::Test {
     helper_.reset(new GLES2CmdHelper(command_buffer_.get()));
     helper_->Initialize(kCommandBufferSizeBytes);
     mapped_memory_.reset(new MappedMemoryManager(
-        helper_.get(), MappedMemoryManager::kNoLimit));
+        helper_.get(), base::Bind(&EmptyPoll), MappedMemoryManager::kNoLimit));
     buffer_tracker_.reset(new BufferTracker(mapped_memory_.get()));
   }
 
@@ -127,5 +132,22 @@ TEST_F(BufferTrackerTest, LostContext) {
   buffer_tracker_->RemoveBuffer(kId);
 }
 
+TEST_F(BufferTrackerTest, Unmanage) {
+  const GLuint kId = 123;
+  const GLsizeiptr size = 64;
+
+  BufferTracker::Buffer* buffer = buffer_tracker_->CreateBuffer(kId, size);
+  ASSERT_TRUE(buffer != NULL);
+  EXPECT_EQ(mapped_memory_->bytes_in_use(), static_cast<size_t>(size));
+
+  void* mem = buffer->address();
+  buffer_tracker_->Unmanage(buffer);
+  buffer_tracker_->RemoveBuffer(kId);
+  EXPECT_EQ(mapped_memory_->bytes_in_use(), static_cast<size_t>(size));
+
+  mapped_memory_->Free(mem);
+  EXPECT_EQ(mapped_memory_->bytes_in_use(), static_cast<size_t>(0));
+}
+
 }  // namespace gles2
 }  // namespace gpu