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/ContextState.cpp b/src/libANGLE/ContextState.cpp
index 0d240ff..b846f22 100644
--- a/src/libANGLE/ContextState.cpp
+++ b/src/libANGLE/ContextState.cpp
@@ -86,8 +86,7 @@
       mRenderbuffers(
           AllocateOrGetSharedResourceManager(shareContextState, &ContextState::mRenderbuffers)),
       mSamplers(AllocateOrGetSharedResourceManager(shareContextState, &ContextState::mSamplers)),
-      mFenceSyncs(
-          AllocateOrGetSharedResourceManager(shareContextState, &ContextState::mFenceSyncs)),
+      mSyncs(AllocateOrGetSharedResourceManager(shareContextState, &ContextState::mSyncs)),
       mPaths(AllocateOrGetSharedResourceManager(shareContextState, &ContextState::mPaths)),
       mFramebuffers(new FramebufferManager())
 {