cocoa browser: remove remaining non-MD code

chrome/browser/themes/theme_service_mac.mm

Index: chrome/browser/themes/theme_service_mac.mm
diff --git a/chrome/browser/themes/theme_service_mac.mm b/chrome/browser/themes/theme_service_mac.mm
index 252cc4ba447411fe3b652db4842d228e62054278..16dd6724ab5c6e0103f4b802fa40f6763984f068 100644
--- a/chrome/browser/themes/theme_service_mac.mm
+++ b/chrome/browser/themes/theme_service_mac.mm
@@ -256,34 +256,6 @@ void HSLToHSB(const color_utils::HSL& hsl, CGFloat* h, CGFloat* s, CGFloat* b) {
   // Note that we are not leaking when we assign a retained object to
   // |gradient|; in all cases we cache it before we return.
   switch (id) {
-    case Properties::GRADIENT_FRAME_INCOGNITO:
-    case Properties::GRADIENT_FRAME_INCOGNITO_INACTIVE: {
-      // TODO(avi): can we simplify this?
-      BOOL active = id == Properties::GRADIENT_FRAME_INCOGNITO;
-      NSColor* base_color = [NSColor colorWithCalibratedRed:83/255.0
-                                                      green:108.0/255.0
-                                                       blue:140/255.0
-                                                      alpha:1.0];
-
-      NSColor *start_color =
-          [base_color gtm_colorAdjustedFor:GTMColorationBaseMidtone
-                                     faded:!active];
-      NSColor *end_color =
-          [base_color gtm_colorAdjustedFor:GTMColorationBaseShadow
-                                     faded:!active];
-
-      if (!active) {
-        start_color = [start_color gtm_colorByAdjustingLuminance:0.1
-                                                      saturation:0.5];
-        end_color = [end_color gtm_colorByAdjustingLuminance:0.1
-                                                  saturation:0.5];
-      }
-
-      gradient = [[NSGradient alloc] initWithStartingColor:start_color
-                                               endingColor:end_color];
-      break;
-    }
-
     case Properties::GRADIENT_TOOLBAR:
     case Properties::GRADIENT_TOOLBAR_INACTIVE: {
       NSColor* base_color = [NSColor colorWithCalibratedWhite:0.2 alpha:1.0];