Use container::back() and container::pop_back() for content.

content/browser/accessibility/browser_accessibility_manager.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "build/build_config.h"
@@ skipping 499 matching lines @@
   }
 
   if (active_descendant)
     return active_descendant;
 
   return focus;
 }
 
 bool BrowserAccessibilityManager::NativeViewHasFocus() {
   BrowserAccessibilityDelegate* delegate = GetDelegateFromRootManager();
-  if (delegate)
-    return delegate->AccessibilityViewHasFocus();
-  return false;
+  return delegate && delegate->AccessibilityViewHasFocus();
 }
 
 BrowserAccessibility* BrowserAccessibilityManager::GetFocus() {
   BrowserAccessibilityManager* root_manager = GetRootManager();
   if (!root_manager)
     root_manager = this;
   int32_t focused_tree_id = root_manager->GetTreeData().focused_tree_id;
 
   BrowserAccessibilityManager* focused_manager = nullptr;
   if (focused_tree_id)
-    focused_manager =BrowserAccessibilityManager::FromID(focused_tree_id);
+    focused_manager = BrowserAccessibilityManager::FromID(focused_tree_id);
 
   // BrowserAccessibilityManager::FromID(focused_tree_id) may return nullptr
   // if the tree is not created or has been destroyed.
   if (!focused_manager)
     focused_manager = root_manager;
 
   return focused_manager->GetFocusFromThisOrDescendantFrame();
 }
 
 BrowserAccessibility*
@@ skipping 302 matching lines @@
   if (start_offset < static_cast<int>(start_text_object->GetText().length())) {
     text += start_text_object->GetText().substr(start_offset);
   } else {
     text += start_text_object->GetText();
   }
 
   for (size_t i = 1; i < text_only_objects.size() - 1; ++i) {
     text += text_only_objects[i]->GetText();
   }
 
-  const BrowserAccessibility* end_text_object =
-      text_only_objects[text_only_objects.size() - 1];
+  const BrowserAccessibility* end_text_object = text_only_objects.back();
   if (end_offset <= static_cast<int>(end_text_object->GetText().length())) {
     text += end_text_object->GetText().substr(0, end_offset);
   } else {
     text += end_text_object->GetText();
   }
 
   return text;
 }
 
 void BrowserAccessibilityManager::OnNodeDataWillChange(
@@ skipping 84 matching lines @@
       tree_source(tree_->CreateTreeSource());
   ui::AXTreeSerializer<const ui::AXNode*,
                        ui::AXNodeData,
                        ui::AXTreeData> serializer(tree_source.get());
   ui::AXTreeUpdate update;
   serializer.SerializeChanges(tree_->root(), &update);
   return update;
 }
 
 }  // namespace content