Implement FenceSyncGL.

BUG=angleproject:888

Change-Id: Ie811266ed1cb08d29344fb11cd9afe77f9587cd7
Reviewed-on: https://chromium-review.googlesource.com/263654
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/gl/FunctionsGL.cpp b/src/libANGLE/renderer/gl/FunctionsGL.cpp
index cc20bda..e20249f 100644
--- a/src/libANGLE/renderer/gl/FunctionsGL.cpp
+++ b/src/libANGLE/renderer/gl/FunctionsGL.cpp
@@ -1131,6 +1131,16 @@
         AssignGLEntryPoint(loadProcAddress("glPrimitiveRestartIndex"), &primitiveRestartIndex);
         AssignGLEntryPoint(loadProcAddress("glTexBuffer"), &texBuffer);
         AssignGLEntryPoint(loadProcAddress("glUniformBlockBinding"), &uniformBlockBinding);
+
+        // Extensions
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glClientWaitSync"), &clientWaitSync);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glDeleteSync"), &deleteSync);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glFenceSync"), &fenceSync);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glGetInteger64i_v"), &getInteger64i_v);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glGetInteger64v"), &getInteger64v);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glGetSynciv"), &getSynciv);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glIsSync"), &isSync);
+        AssignGLExtensionEntryPoint(extensions, "GL_ARB_sync", loadProcAddress("glWaitSync"), &waitSync);
     }
 
     // 3.2