Add begin()/end() to WebVector to enable range-based for loops

public/platform/WebVector.h

Index: public/platform/WebVector.h
diff --git a/public/platform/WebVector.h b/public/platform/WebVector.h
index e83a2d0d2cd56d627ae2b4d50fed0c0e3fcfa591..af76961b6d08c806c361e799d7267e5b74ae97c7 100644
--- a/public/platform/WebVector.h
+++ b/public/platform/WebVector.h
@@ -63,7 +63,9 @@ namespace blink {
 template <typename T>
 class WebVector {
 public:
-    typedef T ValueType;
+    using ValueType = T;
+    using iterator = T*;
+    using const_iterator = const T*;
 
     ~WebVector()
     {
@@ -146,6 +148,11 @@ public:
     T* data() { return m_ptr; }
     const T* data() const { return m_ptr; }
 
+    iterator begin() { return data(); }
+    iterator end() { return begin() + m_size; }
+    const_iterator begin() const { return data(); }
+    const_iterator end() const { return begin() + m_size; }
+
     void swap(WebVector<T>& other)
     {
         std::swap(m_ptr, other.m_ptr);