cocoa browser: remove remaining non-MD code

chrome/browser/ui/cocoa/framed_browser_window.mm

Index: chrome/browser/ui/cocoa/framed_browser_window.mm
diff --git a/chrome/browser/ui/cocoa/framed_browser_window.mm b/chrome/browser/ui/cocoa/framed_browser_window.mm
index ca5f0186aa231d6555ebe30703db6efc6463959f..d99f8642207e9c6f166d0faa7af2036d57de0c1c 100644
--- a/chrome/browser/ui/cocoa/framed_browser_window.mm
+++ b/chrome/browser/ui/cocoa/framed_browser_window.mm
@@ -276,14 +276,6 @@ + (BOOL)drawWindowThemeInDirtyRect:(NSRect)dirtyRect
       themeImageColor = themeProvider->GetNSImageColorNamed(themeImageID);
   }
 
-  // If not Material Design, use a gradient if Incognito and no theme image.
-  NSGradient* gradient = nil;
-  if (!ui::MaterialDesignController::IsModeMaterial() &&
-      !themeImageColor && incognito)
-    gradient = themeProvider->GetNSGradient(
-        active ? ThemeProperties::GRADIENT_FRAME_INCOGNITO :
-                 ThemeProperties::GRADIENT_FRAME_INCOGNITO_INACTIVE);
-
   BOOL themed = NO;
   if (themeImageColor) {
     // Default to replacing any existing pixels with the theme image, but if
@@ -303,12 +295,6 @@ + (BOOL)drawWindowThemeInDirtyRect:(NSRect)dirtyRect
     [themeImageColor set];
     NSRectFillUsingOperation(dirtyRect, operation);
     themed = YES;
-  } else if (gradient) {
-    NSPoint startPoint = NSMakePoint(NSMinX(bounds), NSMaxY(bounds));
-    NSPoint endPoint = startPoint;
-    endPoint.y -= kBrowserFrameViewPaintHeight;
-    [gradient drawFromPoint:startPoint toPoint:endPoint options:0];
-    themed = YES;
   }
 
   // Check to see if we have an overlay image.