[1] Lync Web App とは ( 版) <https://support.office.com/ja-jp/article/Lync-Web-App-%e3%81%a8%e3%81%af-6d5ef797-1437-4828-bb8b-d317f46acde9?ui=ja-JP&rs=ja-JP&ad=JP>
Lync Web App for Lync 2013 は、Lync 会議に参加するために使用するブラウザーベースの会議クライアントです。
[2] "Google Chrome no longer supports Lync Web App" message when you join a Lync meeting by using Google Chrome ( 版) <https://support.microsoft.com/en-us/kb/3025563>
Google changes on the Chrome browser affect the usage of Lync Web App in both Mac and Windows. This requires us to change Lync Server and Lync Online in order to deliver a seamless experience for Chrome users. Microsoft is already working on changes to improve the Lync Web App user experience and is expected to release another update in the first quarter of 2015. In the meantime, users will be provided with manual workaround instructions as part of the meeting join experience.
Microsoft plans to remove this manual workaround, add support for 64-bit versions of Chrome in Mac, and continue to improve the Lync Web App experience for all Chrome users in early 2015. We are also working on making it possible for Chrome users to enjoy a full Lync meeting experience even after the planned deprecation of the so-called "Netscape Plug-In API," or NPAPI, that is going to be targeted by Google in April, 2015.