Angular跨域post:在某些浏览器下会失败

我在Angular(1.4.0)中有一个跨域POST请求，在我删除Content-Type标头后，它可以使用Chrome(43+)和Firefox(37+)。

但在使用Safari或iPhone/iPad上的Safari/Chrome时失败。错误信息是:

Failed to load resource: Request header field Content-Type is notAccess-Control-Allow-Headers.

但是在日志中我可以看到:

[Log] original httpProvider defaults (app.js, line 6)
[Log] Content-Type: application/json;charset=utf-8 (app.js, line 7)
[Log] updated httpProvider defaults (app.js, line 13)
[Log] Content-Type: undefined (app.js, line 14)
[Error] Failed to load resource: Request header field Content-Type is not allowed by Access-Control-Allow-Headers. (search, line 0)
...
headers: Object
  Accept: "application/json, text/plain, */*"

因此:报头中没有Content-Type也会出现错误信息。

有什么建议吗?

片段:

var app = angular.module('myApp', []);
app.config(['$httpProvider', function($httpProvider) {
    console.log("original httpProvider defaults");
    console.log("Content-Type:", $httpProvider.defaults.headers.post['Content-Type']);
    //$httpProvider.defaults.useXDomain = true;
    //delete $httpProvider.defaults.headers.common["X-Requested-With"];
    delete $httpProvider.defaults.headers.post['Content-Type'];
    console.log("updated httpProvider defaults");
    console.log("Content-Type:", $httpProvider.defaults.headers.post['Content-Type']);
}]);
app.controller('testController', function($scope, $http, $sce) {
    console.log("testController");
    $scope.url = "http://.../v0/search";
    $scope.data = { "query":"auto" };
    $scope.testPost = function() {
        $http.post($scope.url, $scope.data).
            success(function(data, status, headers, config) {
                console.log("success");
                console.log(data, status, headers, config);
            }).
            error(function(data, status, headers, config) {
                console.log("error");
                console.log(data, status, headers, config);
            });
    }
});