X11: Set window class for content_shell.

content/shell/browser/shell_views.cc

Index: content/shell/browser/shell_views.cc
diff --git a/content/shell/browser/shell_views.cc b/content/shell/browser/shell_views.cc
index f175a46b43e30e8a2aa486c0511c7a21788389fd..80bdf29a2cae21181f52a12305ff03a42fab157c 100644
--- a/content/shell/browser/shell_views.cc
+++ b/content/shell/browser/shell_views.cc
@@ -471,6 +471,8 @@ void Shell::PlatformCreateWindow(int width, int height) {
   views::Widget::InitParams params;
   params.bounds = gfx::Rect(0, 0, width, height);
   params.delegate = new ShellWindowDelegateView(this);
+  params.wm_class_class = "chromium-content_shell";
+  params.wm_class_name = params.wm_class_class;

[Peter Beverloo, 2016/04/12 11:24:40]

Random jotting so that I understand this (nothing actionable)-- 

For non-official Linux builds this is "chromium-browser" by default, but can be
overridden by the CHROME_DESKTOP environment variable.

wm_class_name will be specialized if (a) it's a Chrome App window, or (b) a
custom --user-data-dir has been set. Neither applies to Content Shell, and we
can always add an environment variable later :-).

   window_widget_->Init(params);
 #endif