DevTools: patch browser's Chrome version into Chrome user agents for emulation

third_party/WebKit/Source/devtools/front_end/common/BrowserVersionInfo.js

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+WebInspector.BrowserVersionInfo = {
+    DefaultChromeVersion: "54.0.2834.0",

[dgozman, 2016/09/07 22:06:28]

Let's have this in a default CurrentBrowserVersion.js, with generated one
overriding it.

[luoe, 2016/09/07 22:46:32]

Done.

+
+    _version: "54.0.2834.0",
+
+    /**
+     * @param {string} uaString
+     * @return {string}
+     */
+    patchUserAgentWithCurrentVersion: function(uaString)
+    {
+        if (uaString.indexOf("%s") === -1)
+            return uaString;
+
+        var currentVersion = WebInspector.BrowserVersionInfo._version;
+        if (currentVersion[0] === "@")
+            currentVersion = WebInspector.BrowserVersionInfo.DefaultChromeVersion;
+        console.assert(uaString.indexOf("%s") === uaString.lastIndexOf("%s"), "User agent string contains multiple %s");
+        return String.sprintf(uaString, currentVersion);

[dgozman, 2016/09/07 22:06:28]

I think instead of replacing the version inside, we'd rather generate the
useragent string as a whole.

[luoe, 2016/09/07 22:46:32]

I don't think we have sufficient information to generate the entire user-agent
for most emulated devices.  We want the Nexus 7 user-agent to use the current
Chrome version, but Chrome doesn't know what the latest Nexus build numbers are,
for example.
Unless there's some way to generate all the other user agents too?

+    }
+};