Reland "linux: Fix grabs for popups belonging to ..."

content/browser/renderer_host/render_widget_host_view_gtk.cc

Index: content/browser/renderer_host/render_widget_host_view_gtk.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_gtk.cc b/content/browser/renderer_host/render_widget_host_view_gtk.cc
index e8010b77172fe817ff6400f9e609a1c4c90d0c35..7e93e8484b8de3fa87c5817f49ccee47483a716e 100644
--- a/content/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/content/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -596,35 +596,48 @@ void RenderWidgetHostViewGtk::InitAsPopup(
   gtk_container_add(GTK_CONTAINER(window), view_.get());
   DoPopupOrFullscreenInit(window, pos);
 
-  // The underlying X window needs to be created and mapped by the above code
-  // before we can grab the input devices.
+  // Grab all input for the app. If a click lands outside the bounds of the
+  // popup, WebKit will notice and destroy us. The underlying X window needs to
+  // be created and mapped by the above code before we can grab the input
+  // devices.
   if (NeedsInputGrab()) {
-    // Grab all input for the app. If a click lands outside the bounds of the
-    // popup, WebKit will notice and destroy us. Before doing this we need
-    // to ensure that the the popup is added to the browser's window group,
-    // to allow for the grabs to work correctly.
-    gtk_window_group_add_window(gtk_window_get_group(
-        GTK_WINDOW(gtk_widget_get_toplevel(parent_))), window);
+    // If our parent is in a widget hierarchy that ends with a window, add
+    // ourselves to the same window group to make sure that our GTK grab
+    // covers it.
+    GtkWidget* toplevel = gtk_widget_get_toplevel(parent_);
+    if (toplevel &&
+        GTK_WIDGET_TOPLEVEL(toplevel) &&
+        GTK_IS_WINDOW(toplevel)) {
+      gtk_window_group_add_window(
+          gtk_window_get_group(GTK_WINDOW(toplevel)), window);
+    }
+
+    // Install an application-level GTK grab to make sure that we receive all of
+    // the app's input.
     gtk_grab_add(view_.get());
 
-    // We need for the application to do an X grab as well. However if the app
-    // already has an X grab (as in the case of extension popup), an app grab
-    // will suffice.
+    // We need to install an X grab as well. However if the app already has an X
+    // grab (as in the case of extension popup), an app grab will suffice.
     do_x_grab_ = !gdk_pointer_is_grabbed();
-
-    // Now grab all of X's input.
     if (do_x_grab_) {
+      // Install the grab on behalf our parent window if it and all of its
+      // ancestors are mapped; otherwise, just use ourselves (maybe we're being
+      // shown on behalf of an inactive tab).
+      GdkWindow* grab_window = gtk_widget_get_window(parent_);
+      if (!grab_window || !gdk_window_is_viewable(grab_window))
+        grab_window = gtk_widget_get_window(view_.get());
+
       gdk_pointer_grab(
-          gtk_widget_get_window(parent_),
-          TRUE,  // Only events outside of the window are reported with respect
-                 // to |parent_->window|.
+          grab_window,
+          TRUE,  // Only events outside of the window are reported with
+                 // respect to |parent_->window|.
           static_cast<GdkEventMask>(GDK_BUTTON_PRESS_MASK |
               GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK),
           NULL,
           NULL,
           GDK_CURRENT_TIME);
       // We grab keyboard events too so things like alt+tab are eaten.
-      gdk_keyboard_grab(gtk_widget_get_window(parent_), TRUE, GDK_CURRENT_TIME);
+      gdk_keyboard_grab(grab_window, TRUE, GDK_CURRENT_TIME);
     }
   }
 }