helium/cat: remove tab strip grab handle

cuz it takes up too much of precious space

patches/helium/ui/experiments/compact-action-toolbar.patch

@@ -341,3 +341,20 @@
    }
  
    return !location_bar_model->GetSecureDisplayText().empty();
+--- a/chrome/browser/ui/views/frame/tab_strip_region_view.cc
++++ b/chrome/browser/ui/views/frame/tab_strip_region_view.cc
+@@ -85,6 +85,14 @@ class FrameGrabHandle : public views::Vi
+     // is full.
+     // TODO(tbergquist): Define this relative to the NTB insets again.
+     if (base::CommandLine::ForCurrentProcess()->HasSwitch("remove-grab-handle")) return gfx::Size(0, 0);
++
++    // In CAT layout the horizontal space is very tight and toolbar padding
++    // partially makes up for the drag handle area, so we don't reserve extra
++    // space for an additional grab handle here.
++    if (features::IsHeliumCatEnabled()) {
++      return gfx::Size(0, 0);
++    }
++
+     return gfx::Size(27, 0);
+   }
+ };