Gtk3 ui: Add libgtk3ui as a separate build component

chrome/browser/ui/libgtkui/select_file_dialog_impl.h

Index: chrome/browser/ui/libgtkui/select_file_dialog_impl.h
diff --git a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h b/chrome/browser/ui/libgtkui/select_file_dialog_impl.h
similarity index 92%
rename from chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h
rename to chrome/browser/ui/libgtkui/select_file_dialog_impl.h
index c31e9ddef6d4e131531fb684fccc8674de4b875a..a72226f0a268749045c2f52113c23def05828d88 100644
--- a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h
+++ b/chrome/browser/ui/libgtkui/select_file_dialog_impl.h
@@ -4,8 +4,8 @@
 //
 // This file implements common select dialog functionality between GTK and KDE.
 
-#ifndef CHROME_BROWSER_UI_LIBGTK2UI_SELECT_FILE_DIALOG_IMPL_H_
-#define CHROME_BROWSER_UI_LIBGTK2UI_SELECT_FILE_DIALOG_IMPL_H_
+#ifndef CHROME_BROWSER_UI_LIBGTKUI_SELECT_FILE_DIALOG_IMPL_H_
+#define CHROME_BROWSER_UI_LIBGTKUI_SELECT_FILE_DIALOG_IMPL_H_
 
 #include <stddef.h>
 
@@ -18,7 +18,7 @@
 #include "ui/shell_dialogs/select_file_dialog.h"
 #include "ui/shell_dialogs/select_file_policy.h"
 
-namespace libgtk2ui {
+namespace libgtkui {
 
 // Shared implementation SelectFileDialog used by SelectFileDialogImplGTK
 class SelectFileDialogImpl : public ui::SelectFileDialog {
@@ -84,6 +84,6 @@ class SelectFileDialogImpl : public ui::SelectFileDialog {
   DISALLOW_COPY_AND_ASSIGN(SelectFileDialogImpl);
 };
 
-}  // namespace libgtk2ui
+}  // namespace libgtkui
 
-#endif  // CHROME_BROWSER_UI_LIBGTK2UI_SELECT_FILE_DIALOG_IMPL_H_
+#endif  // CHROME_BROWSER_UI_LIBGTKUI_SELECT_FILE_DIALOG_IMPL_H_