Omit types in most WGSL `var` statements.

Bug: None
Change-Id: Id6ed10d98a550d912784b688c5473f67f1889a8c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/54882
Commit-Queue: Ben Clayton <bclayton@google.com>
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/src/tests/white_box/D3D12DescriptorHeapTests.cpp b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
index 5bfbb6e..dfed91b 100644
--- a/src/tests/white_box/D3D12DescriptorHeapTests.cpp
+++ b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
@@ -44,7 +44,7 @@
             [[stage(vertex)]] fn main(
                 [[builtin(vertex_index)]] VertexIndex : u32
             ) -> [[builtin(position)]] vec4<f32> {
-                var pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
+                var pos = array<vec2<f32>, 3>(
                     vec2<f32>(-1.0,  1.0),
                     vec2<f32>( 1.0,  1.0),
                     vec2<f32>(-1.0, -1.0)
@@ -785,7 +785,7 @@
             [[stage(vertex)]] fn main(
                 [[builtin(vertex_index)]] VertexIndex : u32
             ) -> [[builtin(position)]] vec4<f32> {
-                var pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
+                var pos = array<vec2<f32>, 3>(
                     vec2<f32>(-1.0,  1.0),
                     vec2<f32>( 1.0,  1.0),
                     vec2<f32>(-1.0, -1.0)