Add the calculated WMClass to generated .desktop files.

chrome/browser/web_applications/web_app.h

Index: chrome/browser/web_applications/web_app.h
diff --git a/chrome/browser/web_applications/web_app.h b/chrome/browser/web_applications/web_app.h
index 7ccb33fa1eadfb8a05f5c94a5f75dc9c43720367..a0727e95fd2b76793e101826bd18f211db22e9fd 100644
--- a/chrome/browser/web_applications/web_app.h
+++ b/chrome/browser/web_applications/web_app.h
@@ -18,6 +18,10 @@ class Profile;
 
 namespace web_app {
 
+// Compute a deterministic name based on data in the shortcut_info.
+std::string GenerateApplicationNameFromInfo(
+    const ShellIntegration::ShortcutInfo& shortcut_info);
+
 // Compute a deterministic name based on the URL. We use this pseudo name
 // as a key to store window location per application URLs in Browser and
 // as app id for BrowserWindow, shortcut and jump list.
@@ -54,6 +58,13 @@ void GetIconsInfo(const WebApplicationInfo& app_info,
                   IconInfoList* icons);
 #endif
 
+#if defined(TOOLKIT_GTK)
+// GTK+ windows that correspond to web apps need to have a deterministic (and
+// different) WMClass than normal chrome windows so the window manager groups
+// them as a separate application.
+std::string GetWMClassFromAppName(std::string app_name);
+#endif
+
 namespace internals {
 
 #if defined(OS_WIN)