Add Ganesh support for RGBA_16161616 and RG_half (take 2)

TBR=egdaniel@google.com
Bug: skia:9171
Change-Id: I862c87ba4bd55381b347333cf9ca23cf5389dff6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/220816
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrSurfaceContext.cpp b/src/gpu/GrSurfaceContext.cpp
index b1f8903..02916f1 100644
--- a/src/gpu/GrSurfaceContext.cpp
+++ b/src/gpu/GrSurfaceContext.cpp
@@ -72,9 +72,11 @@
         case GrColorType::kRG_F32:           return false;
         case GrColorType::kRGBA_F32:         return true;
         case GrColorType::kRGB_ETC1:         return false;
-        // Experimental (for P016 and P010)
         case GrColorType::kR_16:             return false;
         case GrColorType::kRG_1616:          return false;
+        // Experimental (for Y416 and mutant P016/P010)
+        case GrColorType::kRGBA_16161616:    return false;
+        case GrColorType::kRG_half:          return false;
     }
     SK_ABORT("Invalid GrColorType");
     return false;
@@ -108,9 +110,11 @@
         case kAlpha_half_as_Red_GrPixelConfig:  return false;
         case kGray_8_as_Lum_GrPixelConfig:      return false;
         case kGray_8_as_Red_GrPixelConfig:      return false;
-        // Experimental (for P016 and P010)
         case kR_16_GrPixelConfig:               return false;
         case kRG_1616_GrPixelConfig:            return false;
+        // Experimental (for Y416 and mutant P016/P010)
+        case kRGBA_16161616_GrPixelConfig:      return false;
+        case kRG_half_GrPixelConfig:            return false;
     }
     SK_ABORT("Invalid GrPixelConfig");
     return false;