Fix GetUniform validation.

We were missing a check for an out-of-bounds Uniform, which could
cause us to miss an error and also give assertion failures.

BUG=angle:571

Change-Id: I844658a82ce13ea179a2358a202733c54bc2c0c7
Reviewed-on: https://chromium-review.googlesource.com/212934
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libGLESv2/validationES.cpp b/src/libGLESv2/validationES.cpp
index 0b7beb7..cb1662c 100644
--- a/src/libGLESv2/validationES.cpp
+++ b/src/libGLESv2/validationES.cpp
@@ -1691,6 +1691,11 @@
         return gl::error(GL_INVALID_OPERATION, false);
     }
 
+    if (!programBinary->isValidUniformLocation(location))
+    {
+        return gl::error(GL_INVALID_OPERATION, false);
+    }
+
     return true;
 }