cc: Fix bugs found by fuzzer due to floating point imprecision.

cc/tiles/picture_layer_tiling.h

Index: cc/tiles/picture_layer_tiling.h
diff --git a/cc/tiles/picture_layer_tiling.h b/cc/tiles/picture_layer_tiling.h
index 44c4a206cc1303ad44d74387176adc074933a47b..d49d22ed23fa1e0d4a2c114d635617e3a940e6d5 100644
--- a/cc/tiles/picture_layer_tiling.h
+++ b/cc/tiles/picture_layer_tiling.h
@@ -237,6 +237,8 @@ class CC_EXPORT PictureLayerTiling {
     int j() const { return tile_j_; }
 
    private:
+    gfx::Rect ComputeGeometryRect() const;
+
     const PictureLayerTiling* tiling_ = nullptr;
     gfx::Size coverage_rect_max_bounds_;
     gfx::Rect coverage_rect_;