Makes the current page dim out when transitioning to instant preview.

chrome/browser/ui/views/frame/contents_container.cc

Index: chrome/browser/ui/views/frame/contents_container.cc
diff --git a/chrome/browser/ui/views/frame/contents_container.cc b/chrome/browser/ui/views/frame/contents_container.cc
index c3056f794c1bae32a7fef3a4d53838dd82a89b5b..084c87f7cda3e1f73fb423c599a5c9d027497a95 100644
--- a/chrome/browser/ui/views/frame/contents_container.cc
+++ b/chrome/browser/ui/views/frame/contents_container.cc
@@ -4,18 +4,33 @@
 
 #include "chrome/browser/views/frame/contents_container.h"
 
+#include "app/slide_animation.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "views/background.h"
+#include "views/widget/root_view.h"
+#include "views/widget/widget.h"
+
+// Min/max opacity of the overlay.
+static const int kMinOpacity = 0;
+static const int kMaxOpacity = 192;
+
 ContentsContainer::ContentsContainer(views::View* active)
     : active_(active),
       preview_(NULL),
       preview_tab_contents_(NULL),
+      active_overlay_(NULL),
       active_top_margin_(0) {
   AddChildView(active_);
 }
 
 ContentsContainer::~ContentsContainer() {
+  // We don't need to explicitly delete active_overlay_ as it'll be deleted by
+  // virtue of being a child window.
 }
 
 void ContentsContainer::MakePreviewContentsActiveContents() {
+  RemoveFade();
+
   active_ = preview_;
   preview_ = NULL;
   Layout();
@@ -52,6 +67,53 @@ gfx::Rect ContentsContainer::GetPreviewBounds() {
   return gfx::Rect(screen_loc, size());
 }
 
+void ContentsContainer::FadeActiveContents() {
+  if (active_overlay_)
+    return;
+
+#if !defined(OS_WIN)
+  // TODO: fix this. I'm disabling as z-order isn't right on linux so that
+  // overlay ends up obscuring the omnibox.
+  return;
+#endif
+
+  overlay_animation_.reset(new SlideAnimation(this));
+  overlay_animation_->SetDuration(300);
+  overlay_animation_->SetSlideDuration(300);
+  overlay_animation_->Show();
+
+  active_overlay_ = views::Widget::CreatePopupWidget(views::Widget::Transparent,
+                                              views::Widget::NotAcceptEvents,
+                                              views::Widget::DeleteOnDestroy,
+                                              views::Widget::MirrorOriginInRTL);
+  active_overlay_->SetOpacity(0);
+  gfx::Point screen_origin;
+  views::View::ConvertPointToScreen(active_, &screen_origin);
+  gfx::Rect overlay_bounds(screen_origin, active_->size());
+  active_overlay_->Init(active_->GetWidget()->GetNativeView(), overlay_bounds);
+  views::View* content_view = new views::View();
+  content_view->set_background(
+      views::Background::CreateSolidBackground(SK_ColorWHITE));
+  active_overlay_->SetContentsView(content_view);
+  active_overlay_->Show();
+  active_overlay_->MoveAbove(active_->GetWidget());
+}
+
+void ContentsContainer::RemoveFade() {
+  overlay_animation_.reset();
+  if (active_overlay_) {
+    active_overlay_->Close();
+    active_overlay_ = NULL;
+  }
+}
+
+void ContentsContainer::AnimationProgressed(const Animation* animation) {
+  active_overlay_->SetOpacity(
+      Tween::ValueBetween(animation->GetCurrentValue(), kMinOpacity,
+                          kMaxOpacity));
+  active_overlay_->GetRootView()->SchedulePaint();
+}
+
 void ContentsContainer::Layout() {
   // The active view always gets the full bounds.
   active_->SetBounds(0, active_top_margin_, width(),