Add side swipe support for Clean Toolbar

The toolbar needs to update its UI when a snapshot for the side swipe
is taken.

Bug: 785756
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: If1735fe80b575608ed625dda3525a51b1689ee49
Reviewed-on: https://chromium-review.googlesource.com/809155Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522452}

ios/chrome/browser/ui/toolbar/clean/toolbar_configuration.h

@@ -19,6 +19,10 @@
 // Style of this configuration.
 @property(nonatomic, assign) ToolbarStyle style;
 
+// Background color of the NTP. Used to do as if the toolbar was transparent and
+// the NTP is visible behind it.
+@property(nonatomic, readonly) UIColor* NTPBackgroundColor;
+
 // Background color of the toolbar.
 @property(nonatomic, readonly) UIColor* backgroundColor;
 

ios/chrome/browser/ui/toolbar/clean/toolbar_configuration.mm

@@ -5,6 +5,7 @@
 #import "ios/chrome/browser/ui/toolbar/clean/toolbar_configuration.h"
 
 #import "ios/chrome/browser/ui/toolbar/clean/toolbar_constants.h"
+#import "ios/chrome/browser/ui/toolbar/public/web_toolbar_controller_constants.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -23,6 +24,16 @@
   return self;
 }
 
+- (UIColor*)NTPBackgroundColor {
+  switch (self.style) {
+    case NORMAL:
+      return [UIColor whiteColor];
+    case INCOGNITO:
+      return [UIColor colorWithWhite:kNTPBackgroundColorBrightnessIncognito
+                               alpha:1.0];
+  }
+}
+
 - (UIColor*)backgroundColor {
   switch (self.style) {
     case NORMAL:

ios/chrome/browser/ui/toolbar/clean/toolbar_coordinator.mm

@@ -230,7 +230,7 @@
   web::NavigationItem* item =
       webState->GetNavigationManager()->GetVisibleItem();
   GURL URL = item ? item->GetURL().GetOrigin() : GURL::EmptyGURL();
-  BOOL isNTP = URL == GURL(kChromeUINewTabURL);
+  BOOL isNTP = (URL == GURL(kChromeUINewTabURL));
 
   // Don't do anything for a live non-ntp tab.
   if (webState == [self getWebState] && !isNTP) {

ios/chrome/browser/ui/toolbar/clean/toolbar_view_controller.mm

@@ -159,11 +159,19 @@
 }
 
 - (void)updateForSideSwipeSnapshotOnNTP:(BOOL)onNTP {
-  // TODO(crbug.com/785756): Implement this.
+  self.progressBar.hidden = YES;
+  if (onNTP) {
+    self.backgroundView.alpha = 1;
+    self.locationBarContainer.hidden = YES;
+    // The back button is visible only if the forward button is enabled.
+    self.backButton.hiddenInCurrentState = !self.forwardButton.enabled;
+  }
 }
 
 - (void)resetAfterSideSwipeSnapshot {
-  // TODO(crbug.com/785756): Implement this.
+  self.backgroundView.alpha = 0;
+  self.locationBarContainer.hidden = NO;
+  self.backButton.hiddenInCurrentState = NO;
 }
 
 - (void)setBackgroundToIncognitoNTPColorWithAlpha:(CGFloat)alpha {
@@ -686,8 +694,7 @@
     _backgroundView = [[UIView alloc] initWithFrame:CGRectZero];
     _backgroundView.translatesAutoresizingMaskIntoConstraints = NO;
     _backgroundView.backgroundColor =
-        [UIColor colorWithWhite:kNTPBackgroundColorBrightnessIncognito
-                          alpha:1.0];
+        self.buttonFactory.toolbarConfiguration.NTPBackgroundColor;
     [self.view insertSubview:_backgroundView atIndex:0];
     AddSameConstraints(self.view, _backgroundView);
   }