Disable GLSL validation in E2E test runner

Currently the GLSL validation takes about an hour longer for certain bot
configurations then other validation. This CL removes the validation of
GLSL from the test runner in order to speed up bots.

A new GLSL test runner will be added which should but it back in line
with other validation programs.

Change-Id: Id6e4c0120dee5fb1ff7a03be9b42703d545a111c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/147242
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
diff --git a/tools/src/cmd/test-runner/main.go b/tools/src/cmd/test-runner/main.go
index 2046a22..fe20ed5 100644
--- a/tools/src/cmd/test-runner/main.go
+++ b/tools/src/cmd/test-runner/main.go
@@ -621,8 +621,8 @@
 		case wgsl:
 			args = append(args, "--validate") // wgsl validation uses Tint, so is always available
 			validate = true
-		case spvasm, glsl:
-			args = append(args, "--validate") // spirv-val and glslang are statically linked, always available
+		case spvasm:
+			args = append(args, "--validate") // spirv-val is statically linked, always available
 			validate = true
 		case hlslDXC:
 			if cfg.dxcPath != "" {
@@ -639,6 +639,9 @@
 				args = append(args, "--xcrun", cfg.xcrunPath)
 				validate = true
 			}
+		case glsl:
+			validate = false
+			// Do nothing for now, will fill in later with validator
 		default:
 			panic("unknown format: " + j.format)
 		}