When normalize coordinate, return instead of assert() when divide by 0

BUG=382988
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/433293002

core/include/fxcrt/fx_coordinates.h

diff --git a/core/include/fxcrt/fx_coordinates.h b/core/include/fxcrt/fx_coordinates.h
index 9a63e2a..6ec3b5e 100644
--- a/core/include/fxcrt/fx_coordinates.h
+++ b/core/include/fxcrt/fx_coordinates.h
@@ -156,7 +156,9 @@
     void		Normalize()
     {
         FX_FLOAT fLen = FXSYS_sqrt(FXT_PSV::x * FXT_PSV::x + FXT_PSV::y * FXT_PSV::y);
-        FXSYS_assert(fLen >= 0.0001f);
+        if (fLen < 0.0001f) {
+            return;
+        }
         FXT_PSV::x = ((baseType)FXT_PSV::x) / fLen;
         FXT_PSV::y = ((baseType)FXT_PSV::y) / fLen;
     }