Allow "GL_INVERT" nvpr fill mode to pass validation

Bug: angleproject:3617
Bug: skia:9214
Change-Id: I11f4e845095cc1ebcbc2717682e945bcf2bb67e3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1679631
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index 43cacf1..8e10477 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -3920,6 +3920,7 @@
 
     switch (fillMode)
     {
+        case GL_INVERT:
         case GL_COUNT_UP_CHROMIUM:
         case GL_COUNT_DOWN_CHROMIUM:
             break;
@@ -4090,6 +4091,7 @@
 
     switch (fillMode)
     {
+        case GL_INVERT:
         case GL_COUNT_UP_CHROMIUM:
         case GL_COUNT_DOWN_CHROMIUM:
             break;
@@ -4152,6 +4154,7 @@
 
     switch (fillMode)
     {
+        case GL_INVERT:
         case GL_COUNT_UP_CHROMIUM:
         case GL_COUNT_DOWN_CHROMIUM:
             break;