Implemented system tray UI for new account management.

ash/system/tray/tray_details_view.cc

Index: ash/system/tray/tray_details_view.cc
diff --git a/ash/system/tray/tray_details_view.cc b/ash/system/tray/tray_details_view.cc
index 1d8e3d8d30b84b1d1f3b34b9d9e7411751859ef6..15bf1791aa696fc7af63474a22d5f4123a658f82 100644
--- a/ash/system/tray/tray_details_view.cc
+++ b/ash/system/tray/tray_details_view.cc
@@ -127,26 +127,31 @@ void TrayDetailsView::TransitionToDefaultView() {
 }
 
 void TrayDetailsView::Layout() {
-  if (!scroller_ || !footer_ || bounds().IsEmpty()) {
+  if (bounds().IsEmpty()) {
     views::View::Layout();
     return;
   }
 
-  scroller_->set_fixed_size(gfx::Size());
-  gfx::Size size = GetPreferredSize();
+  if (scroller_) {
+    scroller_->set_fixed_size(gfx::Size());
+    gfx::Size size = GetPreferredSize();
 
-  // Set the scroller to fill the space above the bottom row, so that the
-  // bottom row of the detailed view will always stay just above the footer.
-  gfx::Size scroller_size = scroll_content_->GetPreferredSize();
-  scroller_->set_fixed_size(gfx::Size(
-      width() + scroller_->GetScrollBarWidth(),
-      scroller_size.height() - (size.height() - height())));
+    // Set the scroller to fill the space above the bottom row, so that the
+    // bottom row of the detailed view will always stay just above the footer.
+    gfx::Size scroller_size = scroll_content_->GetPreferredSize();
+    scroller_->set_fixed_size(
+        gfx::Size(width() + scroller_->GetScrollBarWidth(),
+                  scroller_size.height() - (size.height() - height())));
+  }
 
   views::View::Layout();
-  // Always make sure the footer element is bottom aligned.
-  gfx::Rect fbounds = footer_->bounds();
-  fbounds.set_y(height() - footer_->height());
-  footer_->SetBoundsRect(fbounds);
+
+  if (footer_) {
+    // Always make sure the footer element is bottom aligned.
+    gfx::Rect fbounds = footer_->bounds();
+    fbounds.set_y(height() - footer_->height());
+    footer_->SetBoundsRect(fbounds);
+  }
 }
 
 void TrayDetailsView::OnPaintBorder(gfx::Canvas* canvas) {