Avoid WTF::Vector::at() and operator[] in core/events.

third_party/WebKit/Source/core/events/UIEventWithKeyState.cpp

Index: third_party/WebKit/Source/core/events/UIEventWithKeyState.cpp
diff --git a/third_party/WebKit/Source/core/events/UIEventWithKeyState.cpp b/third_party/WebKit/Source/core/events/UIEventWithKeyState.cpp
index 9ed546e003b93af22a56ef2644245e90b6679c07..7140b8e2e5941d657ad1f8186c105d39ca3c3276 100644
--- a/third_party/WebKit/Source/core/events/UIEventWithKeyState.cpp
+++ b/third_party/WebKit/Source/core/events/UIEventWithKeyState.cpp
@@ -129,9 +129,9 @@ bool UIEventWithKeyState::getModifierState(const String& keyIdentifier) const {
       {"NumLock", PlatformEvent::NumLockOn},
       {"Symbol", PlatformEvent::SymbolKey},
   };
-  for (size_t i = 0; i < WTF_ARRAY_LENGTH(kIdentifiers); ++i) {
-    if (keyIdentifier == kIdentifiers[i].identifier)
-      return m_modifiers & kIdentifiers[i].mask;
+  for (const auto& identifier : kIdentifiers) {
+    if (keyIdentifier == identifier.identifier)
+      return m_modifiers & identifier.mask;
   }
   return false;
 }