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

third_party/WebKit/Source/core/dom/CompositorProxy.cpp

Index: third_party/WebKit/Source/core/dom/CompositorProxy.cpp
diff --git a/third_party/WebKit/Source/core/dom/CompositorProxy.cpp b/third_party/WebKit/Source/core/dom/CompositorProxy.cpp
index d419c254f9fcd717d15977de6207541179122e2b..a10bd04a4ce429c33c94360da431956a69a58e2f 100644
--- a/third_party/WebKit/Source/core/dom/CompositorProxy.cpp
+++ b/third_party/WebKit/Source/core/dom/CompositorProxy.cpp
@@ -98,10 +98,8 @@ static uint32_t compositorMutablePropertiesFromNames(
 static bool sanityCheckMutableProperties(uint32_t properties) {
   // Ensures that we only have bits set for valid mutable properties.
   uint32_t sanityCheckProperties = properties;
-  for (unsigned i = 0; i < WTF_ARRAY_LENGTH(allowedProperties); ++i) {
-    sanityCheckProperties &=
-        ~static_cast<uint32_t>(allowedProperties[i].property);
-  }
+  for (const auto& property : allowedProperties)
+    sanityCheckProperties &= ~static_cast<uint32_t>(property.property);
   return !sanityCheckProperties;
 }
 #endif