Merge gl::Context and gl::ContextState.

This reduces the number of indrections when accessing the Extensions
or Caps structures. It will provide a small speed-up to some methods.
It also cleans up the code.

Bug: angleproject:2966
Change-Id: Idddac70758c42c1c2b75c885d0cacc8a5c458685
Reviewed-on: https://chromium-review.googlesource.com/c/1392391
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Markus Tavenrath <matavenrath@nvidia.com>
diff --git a/src/libANGLE/renderer/renderer_utils.cpp b/src/libANGLE/renderer/renderer_utils.cpp
index 5eb2b06..ed4b629 100644
--- a/src/libANGLE/renderer/renderer_utils.cpp
+++ b/src/libANGLE/renderer/renderer_utils.cpp
@@ -595,7 +595,7 @@
     if (indexTypeOrInvalid != gl::DrawElementsType::InvalidEnum)
     {
         gl::IndexRange indexRange;
-        ANGLE_TRY(context->getGLState().getVertexArray()->getIndexRange(
+        ANGLE_TRY(context->getState().getVertexArray()->getIndexRange(
             context, indexTypeOrInvalid, vertexOrIndexCount, indices, &indexRange));
         ANGLE_TRY(ComputeStartVertex(context->getImplementation(), indexRange, baseVertex,
                                      startVertexOut));