cc: Prevent float-cast-overflow in MapRectInternal.

cc/output/filter_operation.cc

Index: cc/output/filter_operation.cc
diff --git a/cc/output/filter_operation.cc b/cc/output/filter_operation.cc
index 198057a265d9643d150ed8d66123192452813e59..e75b41707ba47250fa8009ae737c55c2c7b7de75 100644
--- a/cc/output/filter_operation.cc
+++ b/cc/output/filter_operation.cc
@@ -336,9 +336,9 @@ gfx::Rect MapRectInternal(const FilterOperation& op,
       SkVector spread = MapStdDeviation(op.amount(), matrix);
       float spread_x = std::abs(spread.x());
       float spread_y = std::abs(spread.y());
-      gfx::Rect result = rect;
+      gfx::RectF result(rect);
       result.Inset(-spread_x, -spread_y, -spread_x, -spread_y);
-      return result;
+      return gfx::ToEnclosingRect(result);
     }
     case FilterOperation::DROP_SHADOW: {
       SkVector spread = MapStdDeviation(op.amount(), matrix);