Rename gl::FenceSync to gl::Sync.

The spec refers to Sync objects, FenceSyncs being a subtype. The
motivation for this fix is to clear up the FenceSync_ entry point for
auto-generation.

BUG=angleproject:1309

Change-Id: I94c440476d701628575e7a3eea68b6dd110f41c3
Reviewed-on: https://chromium-review.googlesource.com/636516
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/null/ContextNULL.cpp b/src/libANGLE/renderer/null/ContextNULL.cpp
index 4facb45..f0a1545 100644
--- a/src/libANGLE/renderer/null/ContextNULL.cpp
+++ b/src/libANGLE/renderer/null/ContextNULL.cpp
@@ -15,7 +15,6 @@
 #include "libANGLE/renderer/null/CompilerNULL.h"
 #include "libANGLE/renderer/null/DisplayNULL.h"
 #include "libANGLE/renderer/null/FenceNVNULL.h"
-#include "libANGLE/renderer/null/FenceSyncNULL.h"
 #include "libANGLE/renderer/null/FramebufferNULL.h"
 #include "libANGLE/renderer/null/ImageNULL.h"
 #include "libANGLE/renderer/null/PathNULL.h"
@@ -24,6 +23,7 @@
 #include "libANGLE/renderer/null/RenderbufferNULL.h"
 #include "libANGLE/renderer/null/SamplerNULL.h"
 #include "libANGLE/renderer/null/ShaderNULL.h"
+#include "libANGLE/renderer/null/SyncNULL.h"
 #include "libANGLE/renderer/null/TextureNULL.h"
 #include "libANGLE/renderer/null/TransformFeedbackNULL.h"
 #include "libANGLE/renderer/null/VertexArrayNULL.h"
@@ -347,9 +347,9 @@
     return new FenceNVNULL();
 }
 
-FenceSyncImpl *ContextNULL::createFenceSync()
+SyncImpl *ContextNULL::createSync()
 {
-    return new FenceSyncNULL();
+    return new SyncNULL();
 }
 
 TransformFeedbackImpl *ContextNULL::createTransformFeedback(const gl::TransformFeedbackState &state)