Improve some naming

chrome/browser/ui/views/frame/opaque_browser_frame_view.cc

Index: chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
diff --git a/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc b/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
index 002a54a1c89b2025c3f03ec9479611be444c39c1..aeafb0ad9459e208933804535174338a507d763b 100644
--- a/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
+++ b/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
@@ -641,7 +641,7 @@ void OpaqueBrowserFrameView::PaintMaximizedFrameBorder(gfx::Canvas* canvas) {
   // the system title bar pref is set, or when maximized on Ubuntu). Hide the
   // gradient in the tab strip (by shifting it up vertically) to avoid a
   // double-gradient effect.
-  if (tp->UsingNativeTheme())
+  if (tp->UsingSystemTheme())
     frame_background_->set_maximized_top_inset(kGTKThemeCondensedFrameTopInset);
 #endif
 
@@ -864,7 +864,7 @@ SkColor OpaqueBrowserFrameView::GetFrameColor() const {
   }
 
   if (browser_view()->IsBrowserTypeNormal() ||
-      platform_observer_->IsUsingNativeTheme()) {
+      platform_observer_->IsUsingSystemTheme()) {
     return GetThemeProvider()->GetColor(color_id);
   }
 
@@ -894,7 +894,7 @@ gfx::ImageSkia* OpaqueBrowserFrameView::GetFrameImage() const {
         IDR_THEME_FRAME_INCOGNITO_INACTIVE : IDR_THEME_FRAME_INACTIVE;
   }
 
-  if (platform_observer_->IsUsingNativeTheme()) {
+  if (platform_observer_->IsUsingSystemTheme()) {
     // We want to use theme images provided by the platform theme when enabled,
     // even if we are an app or popup window.
     return GetThemeProvider()->GetImageSkiaNamed(resource_id);