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/validationES3.cpp b/src/libANGLE/validationES3.cpp
index 4890d32..8b8c0bd 100644
--- a/src/libANGLE/validationES3.cpp
+++ b/src/libANGLE/validationES3.cpp
@@ -2673,8 +2673,8 @@
         return false;
     }
 
-    FenceSync *fenceSync = context->getFenceSync(sync);
-    if (!fenceSync)
+    Sync *syncObject = context->getSync(sync);
+    if (!syncObject)
     {
         context->handleError(InvalidValue() << "Invalid sync object.");
         return false;
@@ -3427,7 +3427,7 @@
         return false;
     }
 
-    if (sync != static_cast<GLsync>(0) && !context->getFenceSync(sync))
+    if (sync != static_cast<GLsync>(0) && !context->getSync(sync))
     {
         context->handleError(InvalidValue());
         return false;
@@ -3450,9 +3450,8 @@
         return false;
     }
 
-    FenceSync *fenceSync = context->getFenceSync(sync);
-
-    if (!fenceSync)
+    Sync *clientWaitSync = context->getSync(sync);
+    if (!clientWaitSync)
     {
         context->handleError(InvalidValue());
         return false;
@@ -3481,8 +3480,8 @@
         return false;
     }
 
-    FenceSync *fenceSync = context->getFenceSync(sync);
-    if (!fenceSync)
+    Sync *waitSync = context->getSync(sync);
+    if (!waitSync)
     {
         context->handleError(InvalidValue());
         return false;