can i use...

caniuse.md

document.head

• iOS 4.3.5: ok
• Android 2.2.1: ok
• Chrome 4: ok
• Firefox 4: ok
• Opera 11: ok
• Safari 5: ok
• IE 9: ok
• IE 8: ng
• polyfill: document.getElementsByTagName("head")[0]

WebSQL

• iOS 4.3.5: ng (openDatabase)
• iOS 5.1.1: ok
• Android 2.2.1: ok
• ISW13HT(HTC-J) Android 4.0.3 では openDatabase が未定義, 4.0.4 にアップデートすると利用可能に

XMLHttpRequest Lv2

• responseType = "document"

• iOS 5.1.1: ng
• iOS 6.1.0: ok
• Android 2.3.6: ng
• Android 4.0.4: ng
• Chrome 26: ok
• Chrome for Android 26: ok

• responseType = "arraybuffer"

• iOS 5.1.1: ng
• iOS 6.0.1: ng
• iOS 6.1.0: ok
• Android 2.3.6: ng
• Android 4.0.4: ng
• Chrome 26: ok
• Chrome for Android 26: ok

• responseType = "blob"

• iOS 5.1.1: ng
• iOS 6.0.1: ng
• iOS 6.1.0: ng
• iOS 6.1.4: part impl
• Android 2.3.6: ng
• Android 4.0.4: ng
• Chrome 26: ok
• Chrome for Android 26: ok

document.getCSSCanvasContext

• iOS 5.1.1: ok
• iOS 6.1: ok
• Androd 2.3.6: ok
• Chrome for Android 27: ok

window.webkitURL

• Chrome 28: ok
• iOS 6.1.4: impl

window.webkitURL.createObjectURL

• Chrome 26: impl
• Chrome for Android 27: impl
• iOS 6.1.4: impl

audio.src = Blob

• Chrome 26: ok
• Safari 6.0.4: ng
• iOS 6.1.4: ng
• Chrome for Android 27: ng

ng なブラウザでは、MediaError.code = 4 でエラーになったり、エラーにならず音が鳴らなかったり (結局音は鳴らない)

var audio = new Audio();
var xhr = new XMLHttpRequest();

xhr.responseType = "blob";
xhr.onload = function() {
    audio.src = window.webkitURL.createObjectURL(xhr.resonse);
};
xhr.open("GET", "foooooo.m4a");
xhr.send(null);

document.body.onclick = function() {
    audio.load(); // MediaError.code = 4; // MEDIA_ERR_SRC_NOT_SUPPORTED
};