Paint tab-loading throbbers into a ui::Layer (reland).

chrome/browser/ui/views/tabs/tab_strip.cc

Index: chrome/browser/ui/views/tabs/tab_strip.cc
diff --git a/chrome/browser/ui/views/tabs/tab_strip.cc b/chrome/browser/ui/views/tabs/tab_strip.cc
index 4698d6fe03272a5e50909e9ac1ad405e9fd185a5..52a3e7348a8d41e5896f6e2bde4756c03c8f6f90 100644
--- a/chrome/browser/ui/views/tabs/tab_strip.cc
+++ b/chrome/browser/ui/views/tabs/tab_strip.cc
@@ -1200,6 +1200,13 @@ bool TabStrip::ShouldPaintTab(const Tab* tab, gfx::Rect* clip) {
   return true;
 }
 
+bool TabStrip::CanPaintThrobberToLayer() const {
+  // Disable layer-painting of throbbers if dragging, if any tab animation is in
+  // progress, or if stacked tabs are enabled.
+  const bool dragging = drag_controller_ && drag_controller_->started_drag();
+  return !touch_layout_ && !dragging && !IsAnimating();
+}
+
 bool TabStrip::IsImmersiveStyle() const {
   return immersive_style_;
 }