API evolution GPUExtent3D.depth -> depthOrArrayLayers (Step 2)

Still leave deprecated `depth` functional as there are some references in
other clients. Using `depth` and `depthOrArrayLayers` at the same time is
invalid. Add DeprecatedAPITests.

Bug: chromium:1176969
Change-Id: Ia06645e4f3c17588323dd36b11f9f3988b2e3aba
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/44640
Commit-Queue: Shrek Shao <shrekshao@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>
diff --git a/examples/CppHelloTriangle.cpp b/examples/CppHelloTriangle.cpp
index dde6162..164ebf2 100644
--- a/examples/CppHelloTriangle.cpp
+++ b/examples/CppHelloTriangle.cpp
@@ -55,7 +55,7 @@
     descriptor.dimension = wgpu::TextureDimension::e2D;
     descriptor.size.width = 1024;
     descriptor.size.height = 1024;
-    descriptor.size.depth = 1;
+    descriptor.size.depthOrArrayLayers = 1;
     descriptor.sampleCount = 1;
     descriptor.format = wgpu::TextureFormat::RGBA8Unorm;
     descriptor.mipLevelCount = 1;