Add RG_88 texture format

Bug: skia:7903
Change-Id: I69b65fc1cfcc2cc5045bb3b75395f9a256ade278
Reviewed-on: https://skia-review.googlesource.com/c/172979
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
diff --git a/src/gpu/vk/GrVkUtil.cpp b/src/gpu/vk/GrVkUtil.cpp
index 674a1b9..6a51359 100644
--- a/src/gpu/vk/GrVkUtil.cpp
+++ b/src/gpu/vk/GrVkUtil.cpp
@@ -25,6 +25,9 @@
         case kRGB_888_GrPixelConfig:
             *format = VK_FORMAT_R8G8B8_UNORM;
             return true;
+        case kRG_88_GrPixelConfig:
+            *format = VK_FORMAT_R8G8_UNORM;
+            return true;
         case kBGRA_8888_GrPixelConfig:
             *format = VK_FORMAT_B8G8R8A8_UNORM;
             return true;
@@ -88,6 +91,8 @@
             return kSBGRA_8888_GrPixelConfig == config;
         case VK_FORMAT_R8G8B8_UNORM:
             return kRGB_888_GrPixelConfig == config;
+        case VK_FORMAT_R8G8_UNORM:
+            return kRG_88_GrPixelConfig == config;
         case VK_FORMAT_A2B10G10R10_UNORM_PACK32:
             return kRGBA_1010102_GrPixelConfig == config;
         case VK_FORMAT_R5G6B5_UNORM_PACK16:
@@ -124,6 +129,7 @@
         case VK_FORMAT_B8G8R8A8_SRGB:
         case VK_FORMAT_R8G8B8A8_SINT:
         case VK_FORMAT_R8G8B8_UNORM:
+        case VK_FORMAT_R8G8_UNORM:
         case VK_FORMAT_A2B10G10R10_UNORM_PACK32:
         case VK_FORMAT_R5G6B5_UNORM_PACK16:
         case VK_FORMAT_B4G4R4A4_UNORM_PACK16: