replace gradient separator with flat color

The smartlist separators is now a plain grey instead of a gradient
color. This is done in order to give Ring a more modern look.

Change-Id: I0a52a57a487a3c4ba3e13e49e31d29288b43cc78
Reviewed-by: Olivier Soldano <olivier.soldano@savoirfairelinux.com>

src/views/HoverTableRowView.mm

@@ -123,15 +123,6 @@
     self.mouseInside = NO;
 }
 
-static NSGradient *gradientWithTargetColor(NSColor *targetColor) {
-    NSArray *colors = [NSArray arrayWithObjects:[targetColor colorWithAlphaComponent:0],
-                       targetColor,
-                       targetColor,
-                       [targetColor colorWithAlphaComponent:0], nil];
-    const CGFloat locations[4] = { 0.0, 0.35, 0.65, 1.0 };
-    return [[NSGradient alloc] initWithColors:colors atLocations:locations colorSpace:[NSColorSpace sRGBColorSpace]];
-}
-
 - (void)drawBackgroundInRect:(NSRect)dirtyRect {
     // Custom background drawing. We don't call super at all.
     [self.backgroundColor set];
@@ -194,10 +185,7 @@ static NSGradient *gradientWithTargetColor(NSColor *targetColor) {
 @end
 
 void DrawSeparatorInRect(NSRect rect) {
-    // Cache the gradient for performance
-    static NSGradient *gradient = nil;
-    if (gradient == nil) {
-        gradient = gradientWithTargetColor([NSColor colorWithSRGBRed:.80 green:.80 blue:.80 alpha:1]);
-    }
-    [gradient drawInRect:rect angle:0];
+    static NSColor *color = [NSColor colorWithSRGBRed:.90 green:.90 blue:.90 alpha:1];
+    [color drawSwatchInRect:rect];
+
 }