Reset Internal D3D12 Device After Test Shutdown

Adds dawn_native::ResetDeviceInternal, which allows us to destroy and
create a new ID3D12Device. The device should be reset after every test
when GPU-based validation is enabled in order to prevent GBV objects
from using a significant amount of memory over time.

Bug: dawn:623
Change-Id: I654d093d993ab0198c6c240bd0f3f843d2762680
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/41340
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Rafael Cintron <rafael.cintron@microsoft.com>
Commit-Queue: Brandon Jones <brandon1.jones@intel.com>

src/tests/DawnTest.cpp

@@ -677,6 +677,11 @@ DawnTestBase::~DawnTestBase() {
     queue = wgpu::Queue();
     device = wgpu::Device();
 
+    // D3D12's GPU-based validation will accumulate objects over time if the backend device is not
+    // destroyed and recreated, so we reset it here.
+    if (IsD3D12() && IsBackendValidationEnabled()) {
+        mBackendAdapter.ResetInternalDeviceForTesting();
+    }
     mWireHelper.reset();
 }
 

src/tests/end2end/DeviceInitializationTests.cpp

@@ -62,7 +62,7 @@ TEST_F(DeviceInitializationTest, DeviceOutlivesInstance) {
                 properties.backendType == desiredProperties.backendType) {
                 // Create the device, destroy the instance, and break out of the loop.
                 dawn_native::DeviceDescriptor deviceDescriptor = {};
-                device = wgpu::Device(adapter.CreateDevice(&deviceDescriptor));
+                device = wgpu::Device::Acquire(adapter.CreateDevice(&deviceDescriptor));
                 instance.reset();
                 break;
             }