Remove categories notified as invalid

ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/chrome/browser/content_suggestions/content_suggestions_mediator.h"
 
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/optional.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 175 matching lines @@
 - (void)contentSuggestionsService:
             (ntp_snippets::ContentSuggestionsService*)suggestionsService
          newSuggestionsInCategory:(ntp_snippets::Category)category {
   [self.dataSink dataAvailable];
 }
 
 - (void)contentSuggestionsService:
             (ntp_snippets::ContentSuggestionsService*)suggestionsService
                          category:(ntp_snippets::Category)category
                   statusChangedTo:(ntp_snippets::CategoryStatus)status {
-  // Update dataSink.
+  if (!ntp_snippets::IsCategoryStatusInitOrAvailable(status)) {
+    // Remove the category from the UI if it is not available.
+    ContentSuggestionsCategoryWrapper* wrapper =
+        [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category];
+    ContentSuggestionsSectionInformation* sectionInfo =
+        self.sectionInformationByCategory[wrapper];
+
+    [self.dataSink clearSection:sectionInfo];
+    [self.sectionInformationByCategory removeObjectForKey:wrapper];
+  }
 }
 
 - (void)contentSuggestionsService:
             (ntp_snippets::ContentSuggestionsService*)suggestionsService
             suggestionInvalidated:
                 (const ntp_snippets::ContentSuggestion::ID&)suggestion_id {
   ContentSuggestionsCategoryWrapper* wrapper =
       [[ContentSuggestionsCategoryWrapper alloc]
           initWithCategory:suggestion_id.category()];
   ContentSuggestionIdentifier* suggestionIdentifier =
@@ skipping 55 matching lines @@
       wrapperWithCategory:category]] = sectionInfo;
 }
 
 - (ContentSuggestionsCategoryWrapper*)categoryWrapperForSectionInfo:
     (ContentSuggestionsSectionInformation*)sectionInfo {
   return [[self.sectionInformationByCategory allKeysForObject:sectionInfo]
       firstObject];
 }
 
 @end