Replace the GLVersion class with gl::Version.

Update code to use gl::Version in as many places as possible to ease ES 3.1
support.

BUG=angleproject:1588

Change-Id: I3490b53a81027cf849dac551a9cc66ce04506144
Reviewed-on: https://chromium-review.googlesource.com/404946
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/validationES.cpp b/src/libANGLE/validationES.cpp
index d261e44..ce8a80a 100644
--- a/src/libANGLE/validationES.cpp
+++ b/src/libANGLE/validationES.cpp
@@ -2882,7 +2882,7 @@
             return false;
         }
 
-        if (!formatInfo.textureSupport(context->getClientMajorVersion(), context->getExtensions()))
+        if (!formatInfo.textureSupport(context->getClientVersion(), context->getExtensions()))
         {
             context->handleError(Error(GL_INVALID_ENUM));
             return false;