Remove invariant declaration in vertex shader for translation from ESSL 3.00 to GLSL <= 4.1

This is a follow-up patch of
https://chromium-review.googlesource.com/408569. This CL removes
invariant declaration in ESSL 3.00 vertex shader, such like:
"
out vec4 foo;
invariant foo;
"

This CL also adds the workarounds in libANGLE.

BUG=chromium:639760
TEST=webgl2_conformance

Change-Id: I568ab51a9a2f5da10d1aff0b63aae8805097e081
Reviewed-on: https://chromium-review.googlesource.com/409157
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/OutputESSL.cpp b/src/compiler/translator/OutputESSL.cpp
index 2223b03..e55d6c5 100644
--- a/src/compiler/translator/OutputESSL.cpp
+++ b/src/compiler/translator/OutputESSL.cpp
@@ -14,6 +14,7 @@
                          ShHashFunction64 hashFunction,
                          NameMap &nameMap,
                          TSymbolTable &symbolTable,
+                         sh::GLenum shaderType,
                          int shaderVersion,
                          bool forceHighp,
                          ShCompileOptions compileOptions)
@@ -22,6 +23,7 @@
                       hashFunction,
                       nameMap,
                       symbolTable,
+                      shaderType,
                       shaderVersion,
                       SH_ESSL_OUTPUT,
                       compileOptions),