expectContents -> expectGPUBufferValuesEqual

Reviewed in https://github.com/gpuweb/cts/pull/592
diff --git a/src/webgpu/examples.spec.ts b/src/webgpu/examples.spec.ts
index 58bd01b..77c86d8 100644
--- a/src/webgpu/examples.spec.ts
+++ b/src/webgpu/examples.spec.ts
@@ -222,7 +222,7 @@
 
   // Use the expectContents helper to check the actual contents of a GPUBuffer.
   // Like shouldReject, it must be awaited.
-  t.expectContents(src, data);
+  t.expectGPUBufferValuesEqual(src, data);
 });
 
 // One of the following two tests should be skipped on most platforms.