Implement support for CHROMIUM_bind_uniform_location.

BUG=angleproject:1353

Change-Id: Ia219ff973de0de2f8e112c276b3ab6319f7d3884
Reviewed-on: https://chromium-review.googlesource.com/334252
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/validationES.cpp b/src/libANGLE/validationES.cpp
index d3efd91..7f6e915 100644
--- a/src/libANGLE/validationES.cpp
+++ b/src/libANGLE/validationES.cpp
@@ -1391,7 +1391,7 @@
         return false;
     }
 
-    if (location == -1)
+    if (program->isIgnoredUniformLocation(location))
     {
         // Silently ignore the uniform command
         return false;