Paint tab-loading throbbers into a ui::Layer.

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 5269e9947f96702fd54e6fc6d967b17fed866020..dc05ac759ca9f940efeb36192cd2da9a5abd9ec4 100644
--- a/chrome/browser/ui/views/tabs/tab_strip.cc
+++ b/chrome/browser/ui/views/tabs/tab_strip.cc
@@ -1220,6 +1220,13 @@ 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_;
 }