Memory manager: buffer uploads (Metal+refactor) - Part 3

Manages a single persistently mapped GPU heap which is sub-allocated
inside of ring-buffer for uploads. To handle larger buffers without additional
unused heaps, ring buffers are created on-demand.

BUG=dawn:28
TEST=dawn_unittests

Change-Id: If4d3e717186895b1409502c1dea5ab751a4776b2
Reviewed-on: https://dawn-review.googlesource.com/c/4440
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Bryan Bernhart <bryan.bernhart@intel.com>

src/tests/end2end/BufferTests.cpp

@@ -180,10 +180,6 @@ TEST_P(BufferSetSubDataTests, SmallDataAtOffset) {
 
 // Stress test for many calls to SetSubData
 TEST_P(BufferSetSubDataTests, ManySetSubData) {
-    // TODO(cwallez@chromium.org): Use ringbuffers for SetSubData on explicit APIs.
-    // otherwise this creates too many resources and can take freeze the driver(?)
-    DAWN_SKIP_TEST_IF(IsMetal());
-
     // Note: Increasing the size of the buffer will likely cause timeout issues.
     // In D3D12, timeout detection occurs when the GPU scheduler tries but cannot preempt the task
     // executing these commands in-flight. If this takes longer than ~2s, a device reset occurs and

src/tests/end2end/CopyTests.cpp

@@ -396,7 +396,7 @@ TEST_P(CopyTests_T2B, Texture2DArrayRegion) {
 
 // Test that copying texture 2D array mips with 256-byte aligned sizes works
 TEST_P(CopyTests_T2B, Texture2DArrayMip) {
-    // TODO(b-brber): Figure out why this test fails on Intel Linux.
+    // TODO(bryan.bernhart@intel.com): Figure out why this test fails on Intel Linux.
     // See https://bugs.chromium.org/p/dawn/issues/detail?id=101
     DAWN_SKIP_TEST_IF(IsLinux() && IsVulkan() && IsIntel());
     constexpr uint32_t kWidth = 256;

src/tests/unittests/RingBufferTests.cpp

@@ -33,7 +33,7 @@ namespace {
 class RingBufferTests : public testing::Test {
   protected:
     void SetUp() override {
-        // TODO(b-brber): Create this device through the adapter.
+        // TODO(bryan.bernhart@intel.com): Create this device through the adapter.
         mDevice = std::make_unique<null::Device>(/*adapter*/ nullptr);
     }
 
@@ -165,7 +165,7 @@ TEST_F(RingBufferTests, RingBufferSubAlloc) {
 
     // In this example, Tick(8) could not reclaim the wasted bytes. The wasted bytes
     // were add to F9's sub-allocation.
-    // TODO(b-brber): Decide if Tick(8) should free these wasted bytes.
+    // TODO(bryan.bernhart@intel.com): Decide if Tick(8) should free these wasted bytes.
 
     ASSERT_EQ(offset, 0u);
     ASSERT_EQ(buffer->GetUsedSize(), frameSizeInBytes * maxNumOfFrames);