[ios] Fix voiceover for NTP

Voiceover reads nothing for NTP tabs in the tab grid.
It should read 'new tab'. Recently, the titles for NTP
tabs were removed to improve the look of the tab grid.
However, this meant that voiceover had nothing to read.

This CL brings back titles for NTP, but instead hides them.
This allows voiceover to read the title, even though it
is not visible.

Bug: 868401
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I37fe3782e6ee68822e59ff1de7ef18e619cece42
Reviewed-on: https://chromium-review.googlesource.com/1152239Reviewed-by: edchin <edchin@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579266}

ios/chrome/browser/ui/tab_grid/grid/grid_cell.h

@@ -31,7 +31,7 @@
 @property(nonatomic, weak) UIImage* icon;
 @property(nonatomic, weak) UIImage* snapshot;
 @property(nonatomic, copy) NSString* title;
-
+@property(nonatomic, assign) BOOL titleHidden;
 @end
 
 // A GridCell for use in animated transitions that only shows selection state

ios/chrome/browser/ui/tab_grid/grid/grid_cell.mm

@@ -62,6 +62,7 @@ void PositionView(UIView* view, CGPoint point) {
 @synthesize icon = _icon;
 @synthesize snapshot = _snapshot;
 @synthesize title = _title;
+@synthesize titleHidden = _titleHidden;
 // Private properties.
 @synthesize topBarHeight = _topBarHeight;
 @synthesize topBar = _topBar;
@@ -141,6 +142,7 @@ void PositionView(UIView* view, CGPoint point) {
   [super prepareForReuse];
   self.itemIdentifier = nil;
   self.title = nil;
+  self.titleHidden = NO;
   self.icon = nil;
   self.snapshot = nil;
   self.selected = NO;
@@ -216,6 +218,11 @@ void PositionView(UIView* view, CGPoint point) {
   _title = title;
 }
 
+- (void)setTitleHidden:(BOOL)titleHidden {
+  self.titleLabel.hidden = titleHidden;
+  _titleHidden = titleHidden;
+}
+
 #pragma mark - Private
 
 // Sets up the top bar with icon, title, and close button.
@@ -350,6 +357,7 @@ void PositionView(UIView* view, CGPoint point) {
   proxy.icon = cell.icon;
   proxy.snapshot = cell.snapshot;
   proxy.title = cell.title;
+  proxy.titleHidden = cell.titleHidden;
   return proxy;
 }
 #pragma mark - GridToTabTransitionView properties.

ios/chrome/browser/ui/tab_grid/grid/grid_item.h

@@ -18,6 +18,7 @@
 
 @property(nonatomic, readonly) NSString* identifier;
 @property(nonatomic, copy) NSString* title;
+@property(nonatomic, assign) BOOL hidesTitle;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_TAB_GRID_GRID_GRID_ITEM_H_

ios/chrome/browser/ui/tab_grid/grid/grid_item.mm

@@ -13,6 +13,7 @@
 @implementation GridItem
 @synthesize identifier = _identifier;
 @synthesize title = _title;
+@synthesize hidesTitle = _hidesTitle;
 
 - (instancetype)initWithIdentifier:(NSString*)identifier {
   DCHECK(identifier);

ios/chrome/browser/ui/tab_grid/grid/grid_view_controller.mm

@@ -502,6 +502,7 @@ NSIndexPath* CreateIndexPath(NSInteger index) {
   cell.theme = self.theme;
   cell.itemIdentifier = item.identifier;
   cell.title = item.title;
+  cell.titleHidden = item.hidesTitle;
   cell.snapshot = nil;
   cell.icon = nil;
   NSString* itemIdentifier = item.identifier;

ios/chrome/browser/ui/tab_grid/tab_grid_mediator.mm

@@ -38,9 +38,10 @@ GridItem* CreateItem(web::WebState* web_state) {
   TabIdTabHelper* tab_helper = TabIdTabHelper::FromWebState(web_state);
   GridItem* item = [[GridItem alloc] initWithIdentifier:tab_helper->tab_id()];
   // chrome://newtab (NTP) tabs have no title.
-  if (!IsURLNtp(web_state->GetVisibleURL())) {
-    item.title = base::SysUTF16ToNSString(web_state->GetTitle());
+  if (IsURLNtp(web_state->GetVisibleURL())) {
+    item.hidesTitle = YES;
   }
+  item.title = base::SysUTF16ToNSString(web_state->GetTitle());
   return item;
 }