Pass shader version to varying link check

Rules for invariant varying (or in/out variable) matching are different
for ESSL 3 and ESSL 1. Use a recently added ANGLE API to choose which
rules to use based on shader version.

Tested by WebGL 2 test deqp/data/gles3/shaders/qualification_order.html

BUG=488372
TEST=WebGL 2 conformance tests

Review URL: https://codereview.chromium.org/1135733006

Cr-Commit-Position: refs/heads/master@{#330335}

gpu/command_buffer/service/program_manager.cc

@@ -1188,6 +1188,8 @@ bool Program::DetectVaryingsMismatch(std::string* conflicting_name) const {
   const VaryingMap* vertex_varyings = &(attached_shaders_[0]->varying_map());
   const VaryingMap* fragment_varyings = &(attached_shaders_[1]->varying_map());
 
+  int shader_version = attached_shaders_[0]->shader_version();
+
   for (VaryingMap::const_iterator iter = fragment_varyings->begin();
        iter != fragment_varyings->end(); ++iter) {
     const std::string& name = iter->first;
@@ -1203,7 +1205,7 @@ bool Program::DetectVaryingsMismatch(std::string* conflicting_name) const {
       continue;
     }
 
-    if (!hit->second.isSameVaryingAtLinkTime(iter->second)) {
+    if (!hit->second.isSameVaryingAtLinkTime(iter->second, shader_version)) {
       *conflicting_name = name;
       return true;
     }