Make File-Picker modal on Linux

ui/shell_dialogs/select_file_dialog.h

Index: ui/shell_dialogs/select_file_dialog.h
diff --git a/ui/shell_dialogs/select_file_dialog.h b/ui/shell_dialogs/select_file_dialog.h
index b5c877b541c361230604320952c5503d91382d50..e7ec4f9035886bd268e54e31142ab607a3c194f0 100644
--- a/ui/shell_dialogs/select_file_dialog.h
+++ b/ui/shell_dialogs/select_file_dialog.h
@@ -170,6 +170,7 @@ class SHELL_DIALOGS_EXPORT SelectFileDialog
                   const base::FilePath::StringType& default_extension,
                   gfx::NativeWindow owning_window,
                   void* params);
+  void Close();
   bool HasMultipleFileTypeChoices();
 
   // Sets the global ShellDialogsDelegate. Defaults to NULL.
@@ -194,6 +195,8 @@ class SHELL_DIALOGS_EXPORT SelectFileDialog
       gfx::NativeWindow owning_window,
       void* params) = 0;
 
+  virtual void CloseImpl() = 0;

[msw, 2015/09/23 17:12:21]

Give this base class a CloseImpl definition that just calls NOTIMPLEMENTED(), so
each implementation doesn't have to define this.

+
   // Returns the global ShellDialogsDelegate instance if any.
   ShellDialogsDelegate* GetShellDialogsDelegate();