Update initial support for <iframe sandbox> in WebKit

This was implemented without a flag, and with the reflected IDL
attribute, in WebKit 532.6:
WebKit/WebKit@c205c4e
https://github.com/WebKit/WebKit/blob/c205c4e7d40da38c5009df548c2316a358a4fca7/WebCore/Configurations/Version.xcconfig

That maps to Chrome 5 + Safari 5 + iOS 4, which also matches exactly
earlier updates based on collector test results:
mdn#7243
mdn#7290
mdn#7402

The handled attribute tokens were "allow-same-origin", "allow-forms",
and "allow-scripts", so update that data to match.

html/elements/iframe.json

@@ -701,7 +701,7 @@
  "spec_url": "https://html.spec.whatwg.org/multipage/iframe-embed-object.html#attr-iframe-sandbox",
  "support": {
  "chrome": {
- "version_added": "4"
+ "version_added": "5"
  },
  "chrome_android": "mirror",
  "edge": {
@@ -720,7 +720,9 @@
  "safari": {
  "version_added": "5"
  },
- "safari_ios": "mirror",
+ "safari_ios": {
+ "version_added": "4"
+ },
  "samsunginternet_android": "mirror",
  "webview_android": "mirror"
  },
@@ -770,7 +772,7 @@
  "spec_url": "https://html.spec.whatwg.org/multipage/browsers.html#attr-iframe-sandbox-allow-forms",
  "support": {
  "chrome": {
- "version_added": "≤49"
+ "version_added": "5"
  },
  "chrome_android": "mirror",
  "edge": "mirror",
@@ -785,9 +787,11 @@
  "opera": "mirror",
  "opera_android": "mirror",
  "safari": {
- "version_added": "≤10.1"
+ "version_added": "5"
+ },
+ "safari_ios": {
+ "version_added": "4"
  },
- "safari_ios": "mirror",
  "samsunginternet_android": "mirror",
  "webview_android": "mirror"
  },
@@ -1017,7 +1021,7 @@
  "spec_url": "https://html.spec.whatwg.org/multipage/browsers.html#attr-iframe-sandbox-allow-same-origin",
  "support": {
  "chrome": {
- "version_added": "≤49",
+ "version_added": "5",
  "notes": "Chrome 70 and earlier block script execution without <code>allow-scripts</code>, even if <code>allow-same-origin</code> is set. For example, any bound handlers for click events of nodes inside an iframe throw an error for blocked script execution."
  },
  "chrome_android": "mirror",
@@ -1033,10 +1037,13 @@
  "opera": "mirror",
  "opera_android": "mirror",
  "safari": {
- "version_added": "≤10.1",
+ "version_added": "5",
+ "notes": "Safari blocks script execution without <code>allow-scripts</code> even if <code>allow-same-origin</code> is set. For example, any bound handlers for click events of nodes inside an iframe throw an error for blocked script execution."
+ },
+ "safari_ios": {
+ "version_added": "4",
  "notes": "Safari blocks script execution without <code>allow-scripts</code> even if <code>allow-same-origin</code> is set. For example, any bound handlers for click events of nodes inside an iframe throw an error for blocked script execution."
  },
- "safari_ios": "mirror",
  "samsunginternet_android": "mirror",
  "webview_android": "mirror"
  },
@@ -1053,7 +1060,7 @@
  "spec_url": "https://html.spec.whatwg.org/multipage/browsers.html#attr-iframe-sandbox-allow-scripts",
  "support": {
  "chrome": {
- "version_added": "≤49"
+ "version_added": "5"
  },
  "chrome_android": "mirror",
  "edge": "mirror",
@@ -1068,9 +1075,11 @@
  "opera": "mirror",
  "opera_android": "mirror",
  "safari": {
- "version_added": "≤10.1"
+ "version_added": "5"
+ },
+ "safari_ios": {
+ "version_added": "4"
  },
- "safari_ios": "mirror",
  "samsunginternet_android": "mirror",
  "webview_android": "mirror"
  },