localStorage导致浏览器崩溃

localStorageTest 在localStorage中存储一个递增的值，直到它达到浏览器的localStorage大小限制 .

function localStorageTest(key, len) {
   var value = window.localStorage.getItem(key); 
   value = (value == null)?"":value;
   var numIters = len - value.length;
   while(numIters--) {
       value += "1";
       window.localStorage.setItem(key, value);
       if (window.localStorage.getItem(key) != value) {
           console.log("limit reached at " + (value.length-1).toString() + " bytes");
           break;
       }
   }
   console.log("stored " + value.length + " bytes");
}

铬：

localStorageTest("1", 80000);
<browser crashed>

火狐：

localStorageTest("1", 50000);
<browser crashed>

怀疑浏览器内存的使用量增加，我写了 localStorageIncrementalTest ，它与 localStorageTest 做了同样的事情，但是使用 setTimeOut 调用在其操作之间放置了5秒的空闲时间 .

var increment = 5000;

function localStorageIncrementalTest(key, len) {
   var value = window.localStorage.getItem(key); 
   value = (value == null)?"":value;
   var numIters = len - value.length;
   var limitReached = false;
   while(numIters--) {
       value += "1";
       window.localStorage.setItem(key, value);
       if (window.localStorage.getItem(key) != value) {
           console.log("limit reached at " + (value.length-1).toString() + " bytes");
           limitReached = true;
           break;
       }
   }
   console.log("stored " + value.length + " bytes");
   if (!limitReached) {
       setTimeout(function() {
           localStorageIncrementalTest(key, len+increment);
       }, 5000);    
   }
}

Chrome：

localStorageIncrementalTest("1", 30000);
stored 30000 bytes
stored 35000 bytes
...
stored 1800000 bytes
<browser crashed>

Firefox：

localStorageIncrementalTest("1", 30000);
stored 30000 bytes
stored 35000 bytes
...
stored 60000 bytes
<browser crashed>

所以 localStorageIncrementalTest 允许我们在崩溃浏览器之前在localStorage中存储比 localStorageTest 更多的内容 .

任何人都可以解释浏览器崩溃背后的原因，以及避免相同的可能解决方案吗？

我使用的是Chrome 28.0.1500.71和Firefox 26.0

Update ：

function getRandomValue(size) {
    var value = "";
    for (var i = 0; i < size; i++) {
            value += Math.ceil(Math.random()*5);
    }
    return value;
}

function localStorageTest2() {
    for (var i = 0; i < 70000; i++) {
        window.localStorage.setItem("1", getRandomValue(20000));
    }
}

Chrome：

localStorageTest2();
<browser crashed>

Firefox：

localStorageTest2();
<browser crashed>

测试 localStorage2 也导致浏览器崩溃 .