[MD] Implement incognito colors as a NativeTheme (for Aura).

ui/native_theme/BUILD.gn

Index: ui/native_theme/BUILD.gn
diff --git a/ui/native_theme/BUILD.gn b/ui/native_theme/BUILD.gn
index 721e317bf0dba7e22abe6bb08949df2eb26720de..bde6dcfea4d8dfa9a1f90d5d4b9cd3be5b830488 100644
--- a/ui/native_theme/BUILD.gn
+++ b/ui/native_theme/BUILD.gn
@@ -28,6 +28,8 @@ component("native_theme") {
     sources += [
       "native_theme_aura.cc",
       "native_theme_aura.h",
+      "native_theme_aura_dark.cc",
+      "native_theme_aura_dark.h",
     ]
 
     if (is_win) {
@@ -38,6 +40,13 @@ component("native_theme") {
     }
   }
 
+  if (is_win) {
+    sources += [
+      "native_theme_win_dark.cc",

[sky, 2015/11/12 21:58:28]

Generally platform specific files end with the platform, eg
native_theme_dark_win. Is there a reason not to do that here?

[Evan Stade, 2015/11/12 22:11:11]

Here is the inheritance chain:

NativeTheme : NativeThemeWin : NativeThemeWinDark

I wanted to add additional specializations on to the end rather than putting
them in the middle. But otherwise no, there's no particular reason
NativeThemeDarkWin wouldn't work.

[sky, 2015/11/12 23:45:52]

I'm not suggesting moving any code, just the name. And I get what you're saying,
but I think Win is the end is generally how we name things like this and works
better with build stuff.

[Evan Stade, 2015/11/13 18:11:40]

changed the name

+      "native_theme_win_dark.h",
+    ]
+  }
+
   defines = [ "NATIVE_THEME_IMPLEMENTATION" ]
 
   deps = [