First stab at touch optimized omnibox auto-complete per sgabriel's mocks.

ui/gfx/native_theme.h

Index: ui/gfx/native_theme.h
diff --git a/ui/gfx/native_theme.h b/ui/gfx/native_theme.h
index 8e7cdfad8bebc28ab678444938d06d0b167c08ef..3f181c156a0b25cb47c78c78e7c0c3a0f4d015db 100644
--- a/ui/gfx/native_theme.h
+++ b/ui/gfx/native_theme.h
@@ -241,6 +241,9 @@ class UI_EXPORT NativeTheme {
     kColorId_TextfieldSelectionColor,
     kColorId_TextfieldSelectionBackgroundFocused,
     kColorId_TextfieldSelectionBackgroundUnfocused,
+    // Colors for 3D controls
+    kColorId_ThreeDLightShadow,
+    kColorId_ThreeDShadow,
     // TODO(benrg): move other hardcoded colors here.
   };