[ios] Change text color to black when editing bookmarks fields.

BUG=855320

Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I4fb596298e417795877400a94fc7d80349c80673
Reviewed-on: https://chromium-review.googlesource.com/1186701Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585804}

ios/chrome/browser/ui/bookmarks/bookmark_edit_view_controller.mm

@@ -515,6 +515,14 @@ const CGFloat kEstimatedTableSectionFooterHeight = 40;
   }
 }
 
+- (void)textFieldDidBeginEditing:(UITextField*)textField {
+  textField.textColor = [BookmarkTextFieldCell textColorForEditing:YES];
+}
+
+- (void)textFieldDidEndEditing:(UITextField*)textField {
+  textField.textColor = [BookmarkTextFieldCell textColorForEditing:NO];
+}
+
 - (BOOL)textFieldShouldReturn:(UITextField*)textField {
   [textField resignFirstResponder];
   return YES;

ios/chrome/browser/ui/bookmarks/bookmark_folder_editor_view_controller.mm

@@ -387,6 +387,14 @@ folderEditorWithBookmarkModel:(bookmarks::BookmarkModel*)bookmarkModel
   [self updateSaveButtonState];
 }
 
+- (void)textFieldDidBeginEditing:(UITextField*)textField {
+  textField.textColor = [BookmarkTextFieldCell textColorForEditing:YES];
+}
+
+- (void)textFieldDidEndEditing:(UITextField*)textField {
+  textField.textColor = [BookmarkTextFieldCell textColorForEditing:NO];
+}
+
 - (BOOL)textFieldShouldReturn:(UITextField*)textField {
   [textField resignFirstResponder];
   return YES;

ios/chrome/browser/ui/bookmarks/cells/bookmark_text_field_item.h

@@ -42,6 +42,9 @@
 // Text field to display the title or the URL of the bookmark node.
 @property(nonatomic, strong) UITextField* textField;
 
+// Returns the appropriate text color to use for the given |editing| state.
++ (UIColor*)textColorForEditing:(BOOL)editing;
+
 @end
 
 @interface LegacyBookmarkTextFieldCell : UITableViewCell

ios/chrome/browser/ui/bookmarks/cells/bookmark_text_field_item.mm

@@ -112,7 +112,7 @@
   self.textField = [[UITextField alloc] init];
   self.textField.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
   self.textField.adjustsFontForContentSizeCategory = YES;
-  self.textField.textColor = [UIColor lightGrayColor];
+  self.textField.textColor = [BookmarkTextFieldCell textColorForEditing:NO];
   self.textField.clearButtonMode = UITextFieldViewModeWhileEditing;
   self.textField.textAlignment = NSTextAlignmentRight;
   [self.textField setContentHuggingPriority:UILayoutPriorityDefaultLow
@@ -153,6 +153,10 @@
   return self;
 }
 
++ (UIColor*)textColorForEditing:(BOOL)editing {
+  return editing ? [UIColor blackColor] : [UIColor lightGrayColor];
+}
+
 - (void)prepareForReuse {
   [super prepareForReuse];
   [self.textField resignFirstResponder];