Addition testing for panels drag and drop.

chrome/browser/ui/panels/panel_manager.cc

Index: chrome/browser/ui/panels/panel_manager.cc
diff --git a/chrome/browser/ui/panels/panel_manager.cc b/chrome/browser/ui/panels/panel_manager.cc
index f19422f421e2794e6e22cb5f5dd5deae694629e0..f84dd5ff7a5f4cdf8e1f38d92ab4a282cb260e40 100644
--- a/chrome/browser/ui/panels/panel_manager.cc
+++ b/chrome/browser/ui/panels/panel_manager.cc
@@ -8,6 +8,7 @@
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/threading/platform_thread.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/window_sizer.h"
 
@@ -36,6 +37,11 @@ scoped_ptr<PanelManager> panel_instance;
 }  // namespace
 
 // static
+int PanelManager::horizontal_spacing() {
+  return kPanelsHorizontalSpacing;
+}
+
+// static
 PanelManager* PanelManager::GetInstance() {
   if (!panel_instance.get()) {
     panel_instance.reset(new PanelManager());