Use unorm shorts for texture coordinates when rendering text.

There are a couple of reasons for this:
- Vulkan does not guarantee conversions from integral vertex attributes
  to floating point shader variables
- This may be faster and more precise on some platforms, as it avoids
  the aforementioned conversion and changes a multiply by a very small
  value to a multiply by a medium-sized value.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1713693002
TBR=bsalomon@google.com

Committed: https://skia.googlesource.com/skia/+/e507ff0460f4f878214b9454fb5b9ab8d64d8063

Review URL: https://codereview.chromium.org/1713693002
diff --git a/include/gpu/GrTypesPriv.h b/include/gpu/GrTypesPriv.h
index e04a912..834c185 100644
--- a/include/gpu/GrTypesPriv.h
+++ b/include/gpu/GrTypesPriv.h
@@ -212,7 +212,7 @@
     kUByte_GrVertexAttribType,   // unsigned byte, e.g. coverage
     kVec4ub_GrVertexAttribType,  // vector of 4 unsigned bytes, e.g. colors
 
-    kVec2s_GrVertexAttribType,   // vector of 2 shorts, e.g. texture coordinates
+    kVec2us_GrVertexAttribType,   // vector of 2 shorts, e.g. texture coordinates
 
     kInt_GrVertexAttribType,
     kUint_GrVertexAttribType,
@@ -235,7 +235,7 @@
     GR_STATIC_ASSERT(3 == kVec4f_GrVertexAttribType);
     GR_STATIC_ASSERT(4 == kUByte_GrVertexAttribType);
     GR_STATIC_ASSERT(5 == kVec4ub_GrVertexAttribType);
-    GR_STATIC_ASSERT(6 == kVec2s_GrVertexAttribType);
+    GR_STATIC_ASSERT(6 == kVec2us_GrVertexAttribType);
     GR_STATIC_ASSERT(7 == kInt_GrVertexAttribType);
     GR_STATIC_ASSERT(8 == kUint_GrVertexAttribType);
     GR_STATIC_ASSERT(SK_ARRAY_COUNT(kCounts) == kGrVertexAttribTypeCount);
@@ -252,7 +252,7 @@
         4*sizeof(float),        // kVec4f_GrVertexAttribType
         1*sizeof(char),         // kUByte_GrVertexAttribType
         4*sizeof(char),         // kVec4ub_GrVertexAttribType
-        2*sizeof(int16_t),      // kVec2s_GrVertexAttribType
+        2*sizeof(int16_t),      // kVec2us_GrVertexAttribType
         sizeof(int32_t),        // kInt_GrVertexAttribType
         sizeof(uint32_t)        // kUint_GrVertexAttribType
     };
@@ -264,7 +264,7 @@
     GR_STATIC_ASSERT(3 == kVec4f_GrVertexAttribType);
     GR_STATIC_ASSERT(4 == kUByte_GrVertexAttribType);
     GR_STATIC_ASSERT(5 == kVec4ub_GrVertexAttribType);
-    GR_STATIC_ASSERT(6 == kVec2s_GrVertexAttribType);
+    GR_STATIC_ASSERT(6 == kVec2us_GrVertexAttribType);
     GR_STATIC_ASSERT(7 == kInt_GrVertexAttribType);
     GR_STATIC_ASSERT(8 == kUint_GrVertexAttribType);
     GR_STATIC_ASSERT(SK_ARRAY_COUNT(kSizes) == kGrVertexAttribTypeCount);
@@ -283,7 +283,7 @@
     GR_STATIC_ASSERT(3 == kVec4f_GrVertexAttribType);
     GR_STATIC_ASSERT(4 == kUByte_GrVertexAttribType);
     GR_STATIC_ASSERT(5 == kVec4ub_GrVertexAttribType);
-    GR_STATIC_ASSERT(6 == kVec2s_GrVertexAttribType);
+    GR_STATIC_ASSERT(6 == kVec2us_GrVertexAttribType);
     GR_STATIC_ASSERT(7 == kInt_GrVertexAttribType);
     GR_STATIC_ASSERT(8 == kUint_GrVertexAttribType);
     GR_STATIC_ASSERT(9 == kGrVertexAttribTypeCount);
@@ -300,7 +300,7 @@
         case kUByte_GrVertexAttribType:
         case kFloat_GrVertexAttribType:
             return kFloat_GrSLType;
-        case kVec2s_GrVertexAttribType:
+        case kVec2us_GrVertexAttribType:
         case kVec2f_GrVertexAttribType:
             return kVec2f_GrSLType;
         case kVec3f_GrVertexAttribType: