ash: Make sure the uber-tray popup is positioned correctly.

ash/system/tray/system_tray.cc

Index: ash/system/tray/system_tray.cc
diff --git a/ash/system/tray/system_tray.cc b/ash/system/tray/system_tray.cc
index ed64a7e2e9dc44f78a42a7656ffb13e71a722a74..23a3df2225f1f34788f127d89f2f300f558af915 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -28,6 +28,7 @@
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/screen.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/views/border.h"
 #include "ui/views/bubble/bubble_delegate.h"
@@ -351,6 +352,20 @@ class SystemTrayBubble : public views::BubbleDelegateView {
     }
   }
 
+  virtual gfx::Rect GetAnchorRect() OVERRIDE {
+    views::Widget* widget = tray_->GetWidget();
+    if (widget->IsVisible()) {
+      gfx::Rect rect = widget->GetWindowScreenBounds();
+      rect.Inset(0, 0, kPaddingFromRightEdgeOfScreen,
+          kPaddingFromBottomOfScreen);
+      return rect;
+    }
+    gfx::Rect rect = gfx::Screen::GetPrimaryMonitorBounds();
+    return gfx::Rect(rect.width() - kPaddingFromRightEdgeOfScreen,
+                     rect.height() - kPaddingFromBottomOfScreen,
+                     0, 0);
+  }
+
   // Overridden from views::View.
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE {
     state->role = ui::AccessibilityTypes::ROLE_WINDOW;