Bug 1372133 - Add SH_REWRITE_TEXELFETCHOFFSET_TO_TEXELFETCH for Mac+Intel. r=lsalzman

MozReview-Commit-ID: 2WV4jKx6Grh

Differential Revision: https://phabricator.services.mozilla.com/D18905

--HG--
extra : moz-landing-system : lando

dom/canvas/WebGLShaderValidator.cpp

@@ -52,9 +52,11 @@ static ShCompileOptions ChooseValidatorCompileOptions(
     options |= SH_REGENERATE_STRUCT_NAMES;
     options |= SH_INIT_OUTPUT_VARIABLES;
 
-    // Work around that Intel drivers on Mac OSX handle for-loop incorrectly.
     if (gl->Vendor() == gl::GLVendor::Intel) {
+      // Work around that Intel drivers on Mac OSX handle for-loop incorrectly.
       options |= SH_ADD_AND_TRUE_TO_LOOP_CONDITION;
+
+      options |= SH_REWRITE_TEXELFETCHOFFSET_TO_TEXELFETCH;
     }
 #endif