Update gl2.h and update entry points.

Some method signatures were updated. Types like GLclampf and GLvoid
were replaced with other equivalents.

BUG=angleproject:1309

Change-Id: I05e8e2072c5a063d87ad96a855b907424661e680
Reviewed-on: https://chromium-review.googlesource.com/475011
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
index 5bd8b12..4e5cc24 100644
--- a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
+++ b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
@@ -249,7 +249,7 @@
                                     const gl::Rectangle &area,
                                     GLenum format,
                                     GLenum type,
-                                    GLvoid *pixels) const
+                                    void *pixels) const
 {
     const auto &glState         = context->getGLState();
     const auto *readFramebuffer = glState.getReadFramebuffer();