Remove ShaderStage that doesn't exist in WebGPU.

Instead it is replaced by one enum in dawn_native and another in utils.

BUG=dawn:22

Change-Id: I094a40c8d4e22b704e59aea60cbefd1f05c5352a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/8800
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
diff --git a/examples/CppHelloTriangle.cpp b/examples/CppHelloTriangle.cpp
index 39a6d93..eb9d7da 100644
--- a/examples/CppHelloTriangle.cpp
+++ b/examples/CppHelloTriangle.cpp
@@ -94,15 +94,15 @@
     initBuffers();
     initTextures();
 
-    dawn::ShaderModule vsModule = utils::CreateShaderModule(device, dawn::ShaderStage::Vertex, R"(
+    dawn::ShaderModule vsModule = utils::CreateShaderModule(device, utils::ShaderStage::Vertex, R"(
         #version 450
         layout(location = 0) in vec4 pos;
         void main() {
             gl_Position = pos;
-        })"
-    );
+        })");
 
-    dawn::ShaderModule fsModule = utils::CreateShaderModule(device, dawn::ShaderStage::Fragment, R"(
+    dawn::ShaderModule fsModule =
+        utils::CreateShaderModule(device, utils::ShaderStage::Fragment, R"(
         #version 450
         layout(set = 0, binding = 0) uniform sampler mySampler;
         layout(set = 0, binding = 1) uniform texture2D myTexture;