The problem has gotten worse with the latest release of the UITK (1.3.1778+16.04.20151217.1-0ubuntu1). With the fix for bug #1523828, popovers are now requesting active focus when they are shown, so the workaround I mentioned in comment #7 is useless.
In gmail, when long pressing on the compose field of a new message, the webview looses focus, which hides the OSK, which resizes the webview, which as a consequence dismisses the context menu. So the context menu has become unusable in gmail.
The problem has gotten worse with the latest release of the UITK (1.3.1778+ 16.04.20151217. 1-0ubuntu1) . With the fix for bug #1523828, popovers are now requesting active focus when they are shown, so the workaround I mentioned in comment #7 is useless.
In gmail, when long pressing on the compose field of a new message, the webview looses focus, which hides the OSK, which resizes the webview, which as a consequence dismisses the context menu. So the context menu has become unusable in gmail.