Bug 1207288. Enable the ANGLE shader validator for WebGL 2. r=jgilbert

ANGLE's shader parser has much better support for ES3 now. Let's
no longer disable it by default.

dom/canvas/WebGL2Context.cpp

@@ -180,8 +180,6 @@ WebGLContext::InitWebGL2()
     mDefaultTransformFeedback = new WebGLTransformFeedback(this, 0);
     mBoundTransformFeedback = mDefaultTransformFeedback;
 
-    mBypassShaderValidation = true;
-
     return true;
 }
 

dom/canvas/WebGLShaderValidator.cpp

@@ -99,7 +99,7 @@ WebGLContext::CreateShaderValidator(GLenum shaderType) const
     if (mBypassShaderValidation)
         return nullptr;
 
-    ShShaderSpec spec = SH_WEBGL_SPEC;
+    ShShaderSpec spec = IsWebGL2() ? SH_WEBGL2_SPEC : SH_WEBGL_SPEC;
     ShShaderOutput outputLanguage = gl->IsGLES() ? SH_ESSL_OUTPUT
                                                  : SH_GLSL_OUTPUT;
 

dom/canvas/test/webgl-mochitest/webgl-util.js

@@ -62,6 +62,7 @@ WebGLUtil = (function() {
     var prefArrArr = [
       ['webgl.force-enabled', true],
       ['webgl.disable-angle', true],
+      ['webgl.bypass-shader-validation', true],
       ['webgl.enable-prototype-webgl2', true],
     ];
     var prefEnv = {'set': prefArrArr};