Use BRGA as internal format on later iOS

BUG=skia:2733

Review URL: https://codereview.chromium.org/1504333007
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index a7a1e8d..43c33d1 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -848,6 +848,9 @@
     } else {
         if (ctxInfo.hasExtension("GL_APPLE_texture_format_BGRA8888")) {
             fConfigTextureSupport[kBGRA_8888_GrPixelConfig] = true;
+            if (version >= GR_GL_VER(3,0) || ctxInfo.hasExtension("GL_EXT_texture_storage")) {
+                fBGRAIsInternalFormat = true;
+            }
         } else if (ctxInfo.hasExtension("GL_EXT_texture_format_BGRA8888")) {
             fConfigTextureSupport[kBGRA_8888_GrPixelConfig] = true;
             fBGRAIsInternalFormat = true;