[Coverity] pass-by-ref instead of pass-by-val

chrome/browser/ui/gtk/find_bar_gtk.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/gtk/find_bar_gtk.h"
 
 #include <gdk/gdkkeysyms.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 400 matching lines @@
 }
 
 void FindBarGtk::AudibleAlert() {
   // This call causes a lot of weird bugs, especially when using the custom
   // frame. TODO(estade): if people complain, re-enable it. See
   // http://crbug.com/27635 and others.
   //
   //   gtk_widget_error_bell(widget());
 }
 
-gfx::Rect FindBarGtk::GetDialogPosition(gfx::Rect avoid_overlapping_rect) {
+gfx::Rect FindBarGtk::GetDialogPosition(
+    const gfx::Rect& avoid_overlapping_rect) {
   bool ltr = !base::i18n::IsRTL();
   // 15 is the size of the scrollbar, copied from ScrollbarThemeChromium.
   // The height is not used.
   // At very low browser widths we can wind up with a negative |dialog_bounds|
   // width, so clamp it to 0.
   GtkAllocation parent_allocation;
   gtk_widget_get_allocation(gtk_widget_get_parent(widget()),
                             &parent_allocation);
   gfx::Rect dialog_bounds = gfx::Rect(ltr ? 0 : 15, 0,
       std::max(0, parent_allocation.width - (ltr ? 15 : 0)), 0);
@@ skipping 562 matching lines @@
   return FALSE;  // Continue propagation.
 }
 
 gboolean FindBarGtk::OnFocusOut(GtkWidget* entry, GdkEventFocus* event) {
   g_signal_handlers_disconnect_by_func(
       gdk_keymap_get_for_display(gtk_widget_get_display(entry)),
       reinterpret_cast<gpointer>(&OnKeymapDirectionChanged), this);
 
   return FALSE;  // Continue propagation.
 }