GLES1: glMultiTexCoord4(f|x)

BUG=angleproject:2306

+ common validation for multitexturing units
+ clang-format

Change-Id: I6eb456c273490e85fc7008e7e11d15e22dd20276
Reviewed-on: https://chromium-review.googlesource.com/987298
Commit-Queue: Lingfeng Yang <lfy@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/Context.cpp b/src/libANGLE/Context.cpp
index e276d7c..7b901c4 100644
--- a/src/libANGLE/Context.cpp
+++ b/src/libANGLE/Context.cpp
@@ -6400,6 +6400,10 @@
                 *type      = GL_FLOAT;
                 *numParams = 3;
                 return true;
+            case GL_CURRENT_TEXTURE_COORDS:
+                *type      = GL_FLOAT;
+                *numParams = 4;
+                return true;
         }
     }