Add blur effect to the popup menu

This CL adds a blur effect for the popup of the popup menu.

Bug: 821765
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ie562e101ef8d43f8721d92aa070260ccdb957a72
Reviewed-on: https://chromium-review.googlesource.com/980312Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546052}

ios/chrome/browser/ui/popup_menu/BUILD.gn

@@ -53,6 +53,7 @@ source_set("popup_menu_ui") {
     "//ios/chrome/browser/ui/popup_menu/cells",
     "//ios/chrome/browser/ui/presenters",
     "//ios/chrome/browser/ui/table_view",
+    "//ios/chrome/browser/ui/table_view:styler",
     "//ios/chrome/browser/ui/util",
     "//ios/chrome/common",
     "//ui/base",

ios/chrome/browser/ui/popup_menu/popup_menu_table_view_controller.mm

@@ -10,6 +10,7 @@
 #import "ios/chrome/browser/ui/commands/browser_commands.h"
 #import "ios/chrome/browser/ui/commands/open_new_tab_command.h"
 #import "ios/chrome/browser/ui/popup_menu/cells/popup_menu_item.h"
+#import "ios/chrome/browser/ui/table_view/chrome_table_view_styler.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -26,6 +27,7 @@ using base::UserMetricsAction;
 #pragma mark - UIViewController
 
 - (void)viewDidLoad {
+  self.styler.tableViewBackgroundColor = nil;
   [super viewDidLoad];
   self.tableView.rowHeight = UITableViewAutomaticDimension;
   self.tableView.sectionHeaderHeight = 0;

ios/chrome/browser/ui/popup_menu/popup_menu_view_controller.mm

@@ -16,6 +16,8 @@ const CGFloat kCornerRadius = 15;
 const CGFloat kShadowRadius = 10;
 const CGFloat kShadowOpacity = 0.3;
 const CGFloat kContentMargin = 8;
+const CGFloat kBlurBackgroundGreyScale = 0.98;
+const CGFloat kBlurBackgroundAlpha = 0.75;
 }  // namespace
 
 @interface PopupMenuViewController ()<UIGestureRecognizerDelegate>
@@ -56,14 +58,33 @@ const CGFloat kContentMargin = 8;
 // Sets the content container view up.
 - (void)setUpContentContainer {
   _contentContainer = [[UIView alloc] init];
-  _contentContainer.backgroundColor = [UIColor whiteColor];
+
+  if (UIAccessibilityIsReduceTransparencyEnabled()) {
+    _contentContainer.backgroundColor =
+        [UIColor colorWithWhite:kBlurBackgroundGreyScale alpha:1];
+  } else {
+    _contentContainer.backgroundColor = [UIColor clearColor];
+    UIBlurEffect* blurEffect =
+        [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
+    UIVisualEffectView* blur =
+        [[UIVisualEffectView alloc] initWithEffect:blurEffect];
+    blur.contentView.backgroundColor =
+        [UIColor colorWithWhite:kBlurBackgroundGreyScale
+                          alpha:kBlurBackgroundAlpha];
+    [_contentContainer addSubview:blur];
+    blur.translatesAutoresizingMaskIntoConstraints = NO;
+    blur.layer.cornerRadius = kCornerRadius;
+    blur.layer.masksToBounds = YES;
+    AddSameConstraints(blur, _contentContainer);
+  }
+
   _contentContainer.layer.cornerRadius = kCornerRadius;
   _contentContainer.layer.shadowRadius = kShadowRadius;
   _contentContainer.layer.shadowOpacity = kShadowOpacity;
   _contentContainer.translatesAutoresizingMaskIntoConstraints = NO;
   _contentContainer.layoutMargins = UIEdgeInsetsMake(
       kContentMargin, kContentMargin, kContentMargin, kContentMargin);
-  // TODO(crbug.com/821765): Add blur effect and update the shadow.
+  // TODO(crbug.com/821765): Add update the shadow.
   [self.view addSubview:_contentContainer];
 }