Add SwapChain::GetCurrentTexture

This is to eventually allow more using swapchain textures as CopySrc and
CopyDst. Note that this commit doesn't add any additional usages.

Because textures can reflect their creation parameters, swapchains now
need to pass in the correct texture descriptor in all code paths. This
requires additional handling in dawn::native error swapchains, and
dawn::wire::client's SwapChain reservation and Device::CreateSwapChain
code.

Tests are added for all of these code paths except
dawn::wire::client::Device::CreateSwapChain because there is no way to
create a Surface in wire tests at the moment (they don't have an
instance).

Bug: dawn:1551
Change-Id: I22d5e909e1e94d48eb52cae57aabff8a7f0c04c1
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/133463
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Loko Kung <lokokung@google.com>

include/dawn/wire/WireClient.h

@@ -71,7 +71,8 @@ class DAWN_WIRE_EXPORT WireClient : public CommandHandler {
     const volatile char* HandleCommands(const volatile char* commands, size_t size) override;
 
     ReservedTexture ReserveTexture(WGPUDevice device, const WGPUTextureDescriptor* descriptor);
-    ReservedSwapChain ReserveSwapChain(WGPUDevice device);
+    ReservedSwapChain ReserveSwapChain(WGPUDevice device,
+                                       const WGPUSwapChainDescriptor* descriptor);
     ReservedDevice ReserveDevice();
     ReservedInstance ReserveInstance();