Change Painter factory functions to unique_ptr

chrome/browser/ui/libgtkui/gtk_ui.cc

Index: chrome/browser/ui/libgtkui/gtk_ui.cc
diff --git a/chrome/browser/ui/libgtkui/gtk_ui.cc b/chrome/browser/ui/libgtkui/gtk_ui.cc
index 9c25e84dd050a1e27885731c70acb6dd99c101b5..8b3a24d77682549a15f5f720701491598903a4ac 100644
--- a/chrome/browser/ui/libgtkui/gtk_ui.cc
+++ b/chrome/browser/ui/libgtkui/gtk_ui.cc
@@ -687,17 +687,18 @@ std::unique_ptr<views::Border> GtkUi::CreateNativeBorder(
       owning_button->GetClassName() == views::BlueButton::kViewClassName;
 
   for (unsigned i = 0; i < arraysize(paintstate); i++) {
-    views::Painter* painter = nullptr;
+    std::unique_ptr<views::Painter> painter = nullptr;

[msw, 2017/01/19 09:46:53]

nit: |= nullptr| no longer needed.

[Evan Stade, 2017/01/19 16:26:29]

Done.

 
     if (border->PaintsButtonState(paintstate[i].focus, paintstate[i].state)) {
       std::string idr = is_blue ? paintstate[i].idr_blue : paintstate[i].idr;
-      painter = new GtkButtonPainter(idr);
+      painter = base::MakeUnique<GtkButtonPainter>(idr);
     }
 
-    gtk_border->SetPainter(paintstate[i].focus, paintstate[i].state, painter);
+    gtk_border->SetPainter(paintstate[i].focus, paintstate[i].state,

[msw, 2017/01/19 09:46:53]

optional nit/q: i wonder if we can just skip SetPainter for null painters and
simplify this block:
  for (unsigned i = 0; i < arraysize(paintstate); i++) {
    if (border->PaintsButtonState(paintstate[i].focus, paintstate[i].state)) {
      std::string idr = is_blue ? paintstate[i].idr_blue : paintstate[i].idr;
      gtk_border->SetPainter(paintstate[i].focus, paintstate[i].state,
                             base::MakeUnique<GtkButtonPainter>(idr));
    }
  }

[Evan Stade, 2017/01/19 16:26:29]

I think you're right, done.

+                           std::move(painter));
   }
 
-  return std::move(gtk_border);
+  return gtk_border;
 }
 
 void GtkUi::AddWindowButtonOrderObserver(