Ensure WGSL StringView knows length

When ShaderModule passes a WGSL string it first converts to const char*
and then StringView. This discards length information and requires
strlen() to be used to figure out length again later. Don't discard the
length information to avoid this.

Bug: none
Change-Id: I910a2680f3e373049f211f2a1f19c06a9e789a14
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/239656
Commit-Queue: Kyle Charbonneau <kylechar@google.com>
Reviewed-by: dan sinclair <dsinclair@chromium.org>

src/dawn/native/ShaderModule.cpp

diff --git a/src/dawn/native/ShaderModule.cpp b/src/dawn/native/ShaderModule.cpp
index c255eed..cce91b8 100644
--- a/src/dawn/native/ShaderModule.cpp
+++ b/src/dawn/native/ShaderModule.cpp
@@ -1651,7 +1651,7 @@
                 descriptor.nextInChain = &spirvDescriptor;
                 break;
             case Type::Wgsl:
-                wgslDescriptor.code = mWgsl.c_str();
+                wgslDescriptor.code = std::string_view(mWgsl);
                 descriptor.nextInChain = &wgslDescriptor;
                 break;
             default: