<!DOCTYPE html> <!-- webkit-test-runner [ LayoutFormattingContextEnabled=true InlineFormattingContextIntegrationEnabled=false ] -->
<style>
.container {
  width: 100px;
  height: 100px;
}

.floatBox {
  float: left;
  width: 40px;
  height: 100px;
  background-color: green;
}

.floatAvoider {
  overflow: hidden; 
  height: 100%;
  background-color: blue;
  max-width: 10%;
}
</style>
<div class=container>
  <div class=floatBox></div>
  <div class=floatAvoider></div>
</div>