Created new PanelStrip base class and make DockedPanelStrip and OverflowPanelStrip its subclasses.

chrome/browser/ui/panels/panel_browsertest.cc

Index: chrome/browser/ui/panels/panel_browsertest.cc
diff --git a/chrome/browser/ui/panels/panel_browsertest.cc b/chrome/browser/ui/panels/panel_browsertest.cc
index 1c4bbd15966501ae87791a0ed59ead2cdd6ed71d..29636a630e9dfffee5e6ebb59bc818474c1a00d5 100644
--- a/chrome/browser/ui/panels/panel_browsertest.cc
+++ b/chrome/browser/ui/panels/panel_browsertest.cc
@@ -968,7 +968,7 @@ IN_PROC_BROWSER_TEST_F(PanelBrowserTest, MinimizeRestore) {
   CreatePanelWithBounds("PanelTest1", gfx::Rect(0, 0, 100, 100));
   TestMinimizeRestore();
 
-  PanelManager::GetInstance()->RemoveAll();
+  PanelManager::GetInstance()->CloseAll();
 }
 
 IN_PROC_BROWSER_TEST_F(PanelBrowserTest, MinimizeRestoreTwoPanels) {
@@ -981,7 +981,7 @@ IN_PROC_BROWSER_TEST_F(PanelBrowserTest, MinimizeRestoreTwoPanels) {
   CreatePanelWithBounds("PanelTest2", gfx::Rect(0, 0, 110, 110));
   TestMinimizeRestore();
 
-  PanelManager::GetInstance()->RemoveAll();
+  PanelManager::GetInstance()->CloseAll();
 }
 
 IN_PROC_BROWSER_TEST_F(PanelBrowserTest, MinimizeRestoreThreePanels) {
@@ -995,7 +995,7 @@ IN_PROC_BROWSER_TEST_F(PanelBrowserTest, MinimizeRestoreThreePanels) {
   CreatePanelWithBounds("PanelTest3", gfx::Rect(0, 0, 120, 120));
   TestMinimizeRestore();
 
-  PanelManager::GetInstance()->RemoveAll();
+  PanelManager::GetInstance()->CloseAll();
 }
 
 IN_PROC_BROWSER_TEST_F(PanelBrowserTest, ActivatePanelOrTabbedWindow) {