Build with -Wextra-semi

Bug: chromium:1355871
Change-Id: Id6c9774e7f7a86837f02cddfea0b36724e7c609e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/100343
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
diff --git a/src/dawn/common/BUILD.gn b/src/dawn/common/BUILD.gn
index ef8400c..f46d108 100644
--- a/src/dawn/common/BUILD.gn
+++ b/src/dawn/common/BUILD.gn
@@ -115,6 +115,7 @@
       "-Wdeprecated-copy",
       "-Wdeprecated-copy-dtor",
       "-Wduplicate-enum",
+      "-Wextra-semi",
       "-Wextra-semi-stmt",
       "-Wimplicit-fallthrough",
       "-Winconsistent-missing-destructor-override",
diff --git a/src/dawn/native/metal/BackendMTL.mm b/src/dawn/native/metal/BackendMTL.mm
index fdd27bf..acba1a9 100644
--- a/src/dawn/native/metal/BackendMTL.mm
+++ b/src/dawn/native/metal/BackendMTL.mm
@@ -406,7 +406,7 @@
         if (mDeviceId != 0) {
             mArchitectureName = gpu_info::GetArchitectureName(mVendorId, mDeviceId);
         }
-    };
+    }
 
     enum class MTLGPUFamily {
         Apple1,