Initialize our quads to zero before we gl_->BufferData() with them.

cc/output/geometry_binding.h

Index: cc/output/geometry_binding.h
diff --git a/cc/output/geometry_binding.h b/cc/output/geometry_binding.h
index ef08b7d079b0148fdd568b940e556c64b9799710..ae6868744c38c5ca421471e0594e572645acf8a4 100644
--- a/cc/output/geometry_binding.h
+++ b/cc/output/geometry_binding.h
@@ -29,10 +29,23 @@ struct GeometryBindingVertex {
 };
 
 struct GeometryBindingQuad {
+  GeometryBindingQuad();
+  GeometryBindingQuad(const GeometryBindingVertex& vert0,
+                      const GeometryBindingVertex& vert1,
+                      const GeometryBindingVertex& vert2,
+                      const GeometryBindingVertex& vert3);
   GeometryBindingVertex v0, v1, v2, v3;
 };
 
 struct GeometryBindingQuadIndex {
+  GeometryBindingQuadIndex();
+  GeometryBindingQuadIndex(uint16 index0,
+                           uint16 index1,
+                           uint16 index2,
+                           uint16 index3,
+                           uint16 index4,
+                           uint16 index5);
+
   uint16 data[6];
 };