Fixes go test failures and issues from dawn/98241.

Change-Id: Idf4f47eba595dcf3f2c44b5f73179b2773a68aef
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/98761
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

tools/src/cts/expectations/expectations.go

@@ -81,6 +81,7 @@ type Expectation struct {
 	Comment string      // Optional comment at end of line
 }
 
+// Expectations are a list of Expectation
 type Expectations []Expectation
 
 // Load loads the expectation file at 'path', returning a Content.

tools/src/cts/expectations/update_test.go

@@ -169,8 +169,8 @@ a:b,c:* [ Failure ]
 		{ //////////////////////////////////////////////////////////////////////
 			name: "simple expectation with tags",
 			expectations: `
-[ os-a ] a:b,c:* [ Failure ]
 [ gpu-b ] a:b,c:* [ Failure ]
+[ os-a ] a:b,c:* [ Failure ]
 `,
 			results: result.List{
 				result.Result{
@@ -186,7 +186,7 @@ a:b,c:* [ Failure ]
 				{
 					Severity: expectations.Error,
 					Line:     headerLines + 3,
-					Message:  "[gpu-b] a:b,c:* collides with expectation at line 8",
+					Message:  "[os-a] a:b,c:* collides with expectation at line 8",
 				},
 			},
 		},
@@ -219,8 +219,8 @@ a:b,c:* [ Failure ]
 		{ //////////////////////////////////////////////////////////////////////
 			name: "collision with child-expectation",
 			expectations: `
-a:b:x:* [ Failure ]
-a:b:* [ Failure ]
+crbug.com/a/1 a:b:x:* [ Failure ]
+crbug.com/a/2 a:b:* [ Failure ]
 `,
 			results: result.List{
 				result.Result{
@@ -235,7 +235,7 @@ a:b:* [ Failure ]
 				},
 			},
 			updated: `
-a:b:x:* [ Failure ]
+crbug.com/a/1 a:b:x:* [ Failure ]
 
 # New failures. Please triage:
 crbug.com/dawn/0000 a:b:y:* [ Failure ]