Support detaching/attaching panels via inter-strip drags.

chrome/browser/ui/panels/panel_browser_window_cocoa.mm

Index: chrome/browser/ui/panels/panel_browser_window_cocoa.mm
diff --git a/chrome/browser/ui/panels/panel_browser_window_cocoa.mm b/chrome/browser/ui/panels/panel_browser_window_cocoa.mm
index bfb64c41c99ab43b564bf5750e7129d2bb1ef094..958fcd6d86de24be59e0c174e9f28e5160909181 100644
--- a/chrome/browser/ui/panels/panel_browser_window_cocoa.mm
+++ b/chrome/browser/ui/panels/panel_browser_window_cocoa.mm
@@ -39,6 +39,16 @@ NSRect ConvertCoordinatesToCocoa(const gfx::Rect& bounds) {
       bounds.width(), bounds.height());
 }
 
+// Converts a point from the platfrom-independent screen coordinates (with the
+// (0,0) in the top-left corner of the primary screen) to the Cocoa screen
+// coordinates (with (0,0) in the low-left corner).
+NSPoint ConvertPointToCocoaCoordinates(const gfx::Point& point) {
+  // Flip coordinates based on the primary screen.
+  NSScreen* screen = [[NSScreen screens] objectAtIndex:0];
+
+  return NSMakePoint(point.x(), NSHeight([screen frame]) - point.y());
+}
+
 }  // namespace
 
 // This creates a shim window class, which in turn creates a Cocoa window
@@ -266,6 +276,10 @@ void PanelBrowserWindowCocoa::SetPanelAppIconVisibility(bool visible) {
   // TODO(dimich): to be implemented.
 }
 
+void PanelBrowserWindowCocoa::SetPanelAlwaysOnTop(bool on_top) {
+  [controller_ setAlwaysOnTop:on_top];
+}
+
 void PanelBrowserWindowCocoa::DidCloseNativeWindow() {
   DCHECK(!isClosed());
   panel_->OnNativePanelClosed();
@@ -310,9 +324,10 @@ class NativePanelTestingCocoa : public NativePanelTesting {
   NativePanelTestingCocoa(NativePanel* native_panel);
   virtual ~NativePanelTestingCocoa() { }
   // Overridden from NativePanelTesting
-  virtual void PressLeftMouseButtonTitlebar(const gfx::Point& point) OVERRIDE;
+  virtual void PressLeftMouseButtonTitlebar(
+      const gfx::Point& mouse_location) OVERRIDE;
   virtual void ReleaseMouseButtonTitlebar() OVERRIDE;
-  virtual void DragTitlebar(int delta_x, int delta_y) OVERRIDE;
+  virtual void DragTitlebar(const gfx::Point& mouse_location) OVERRIDE;
   virtual void CancelDragTitlebar() OVERRIDE;
   virtual void FinishDragTitlebar() OVERRIDE;
   virtual bool VerifyDrawingAttention() const OVERRIDE;
@@ -340,16 +355,17 @@ PanelTitlebarViewCocoa* NativePanelTestingCocoa::titlebar() const {
 }
 
 void NativePanelTestingCocoa::PressLeftMouseButtonTitlebar(
-  const gfx::Point& point) {
-  [titlebar() pressLeftMouseButtonTitlebar];
+    const gfx::Point& mouse_location) {
+  [titlebar() pressLeftMouseButtonTitlebar:ConvertPointToCocoaCoordinates(
+      mouse_location)];
 }
 
 void NativePanelTestingCocoa::ReleaseMouseButtonTitlebar() {
   [titlebar() releaseLeftMouseButtonTitlebar];
 }
 
-void NativePanelTestingCocoa::DragTitlebar(int delta_x, int delta_y) {
-  [titlebar() dragTitlebarDeltaX:delta_x deltaY:delta_y];
+void NativePanelTestingCocoa::DragTitlebar(const gfx::Point& mouse_location) {
+  [titlebar() dragTitlebar:ConvertPointToCocoaCoordinates(mouse_location)];
 }
 
 void NativePanelTestingCocoa::CancelDragTitlebar() {