[VrShell] Centralize color handling and enable close button on fullscreen

chrome/browser/android/vr_shell/color_scheme.h

Index: chrome/browser/android/vr_shell/color_scheme.h
diff --git a/chrome/browser/android/vr_shell/color_scheme.h b/chrome/browser/android/vr_shell/color_scheme.h
index ebbed05f57c648c06addb7ec75c328016008560a..8457c8139a820751f83d3a3820f0dd550e762f65 100644
--- a/chrome/browser/android/vr_shell/color_scheme.h
+++ b/chrome/browser/android/vr_shell/color_scheme.h
@@ -21,21 +21,34 @@ struct ColorScheme {
 
   // These colors should be named generically, if possible, so that they can be
   // meaningfully reused by multiple elements.
-  SkColor horizon;
+  SkColor world_background;
   SkColor floor;
   SkColor ceiling;
   SkColor floor_grid;
 
   // The foreground color is used for text and sometimes for icons.
-  SkColor foreground;
-  SkColor emphasized;
-  SkColor deemphasized;
+  SkColor element_foreground;
+  // The background color is used behind text or icons in the foreground color.
+  // The related hover and down colors are to be used for buttons.
+  SkColor element_background;
+  SkColor element_background_hover;
+  SkColor element_background_down;
 
-  // This is the background color. To be used behind text in the foreground
-  // color. The related hover and down colors are to be used for buttons.
-  SkColor background;
-  SkColor background_hover;
-  SkColor background_down;
+  // Specific element background and foregrounds
+  SkColor close_button_foreground;
+  SkColor close_button_background;
+  SkColor close_button_background_hover;
+  SkColor close_button_background_down;
+  SkColor loading_indicator_background;
+  SkColor loading_indicator_foreground;
+  SkColor exit_warning_background;
+  SkColor exit_warning_foreground;
+  SkColor transient_warning_background;
+  SkColor transient_warning_foreground;
+  SkColor permanent_warning_background;
+  SkColor permanent_warning_foreground;
+  SkColor system_indicator_background;
+  SkColor system_indicator_foreground;
 
   // If you have a segmented element, its separators should use this color.
   SkColor separator;
@@ -45,13 +58,15 @@ struct ColorScheme {
   SkColor secure;
   SkColor insecure;
   SkColor warning;
+  SkColor url_emphasized;
+  SkColor url_deemphasized;
 
   // The color used for disabled icons.
   SkColor disabled;
 
-  // Colors used for the loading progress bar indicator.
-  SkColor loading_background;
-  SkColor loading_foreground;
+  // Screen dimmer colors.
+  SkColor dimmer_outer;
+  SkColor dimmer_inner;
 };
 
 }  // namespace vr_shell