GTK: Make the drawing of selected tabs use the throb value.

Previously, we used a different inactive tab image, but that had the problem
that selected background tabs that were showing the throbber would show the
normal tab image within the throbber bounds. This makes us match how views
renders.

BUG=none
TEST=Have a non-active, selected tab show the throbber. The area behind the throbber should match the rest of the tab.


Review URL: http://codereview.chromium.org/8429012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@108049 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc

@@ -74,6 +74,12 @@ const int kHoverDurationMs = 90;
 // How opaque to make the hover state (out of 1).
 const double kHoverOpacity = 0.33;
 
+// Opacity for non-active selected tabs.
+const double kSelectedTabOpacity = 0.45;
+
+// Selected (but not active) tabs have their throb value scaled down by this.
+const double kSelectedTabThrobScale = 0.5;
+
 // Max opacity for the mini-tab title change animation.
 const double kMiniTitleChangeThrobOpacity = 0.75;
 
@@ -945,8 +951,6 @@ void TabRendererGtk::PaintInactiveTabBackground(GtkWidget* widget,
                                                      cairo_t* cr) {
   int theme_id = data_.incognito ?
       IDR_THEME_TAB_BACKGROUND_INCOGNITO : IDR_THEME_TAB_BACKGROUND;
-  if (IsSelected())
-    theme_id = IDR_THEME_TAB_BACKGROUND_V;
 
   CairoCachedSurface* tab_bg =
       theme_service_->GetSurfaceNamed(theme_id, widget);
@@ -1024,12 +1028,19 @@ CustomDrawButton* TabRendererGtk::MakeCloseButton() {
 }
 
 double TabRendererGtk::GetThrobValue() {
+  bool is_selected = IsSelected();
+  double min = is_selected ? kSelectedTabOpacity : 0;
+  double scale = is_selected ? kSelectedTabThrobScale : 1;
+
   if (mini_title_animation_.get() && mini_title_animation_->is_animating()) {
     return mini_title_animation_->GetCurrentValue() *
-        kMiniTitleChangeThrobOpacity;
+        kMiniTitleChangeThrobOpacity * scale + min;
   }
-  return hover_animation_.get() ?
-      kHoverOpacity * hover_animation_->GetCurrentValue() : 0;
+
+  if (hover_animation_.get())
+    return kHoverOpacity * hover_animation_->GetCurrentValue() * scale + min;
+
+  return is_selected ? kSelectedTabOpacity : 0;
 }
 
 void TabRendererGtk::CloseButtonClicked() {