Triage Dawn TODOs

Change-Id: Ia049d5a03d0e251531f71def525492403588fd74
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/53460
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

src/utils/TerribleCommandBuffer.cpp

@@ -34,9 +34,7 @@ namespace utils {
     }
 
     void* TerribleCommandBuffer::GetCmdSpace(size_t size) {
-        // TODO(kainino@chromium.org): Should we early-out if size is 0?
-        //   (Here and/or in the caller?) It might be good to make the wire receiver get a nullptr
-        //   instead of pointer to zero-sized allocation in mBuffer.
+        // Note: This returns non-null even if size is zero.
         if (size > sizeof(mBuffer)) {
             return nullptr;
         }

src/utils/TestUtils.cpp

@@ -36,7 +36,7 @@ namespace utils {
         wgpu::Extent3D textureSizeAtLevel0,
         uint32_t mipmapLevel,
         uint32_t rowsPerImage) {
-        // TODO(jiawei.shao@intel.com): support compressed texture formats
+        // Compressed texture formats not supported in this function yet.
         ASSERT(utils::GetTextureFormatBlockWidth(format) == 1);
 
         TextureDataCopyLayout layout;