Fix virtual/override/final usage in Source/platform/.

Source/platform/text/LineEnding.cpp

Index: Source/platform/text/LineEnding.cpp
diff --git a/Source/platform/text/LineEnding.cpp b/Source/platform/text/LineEnding.cpp
index a37e63cf1e8a72be6c30f35d1a71c4b1f35d87fa..143b6e29962dc4facb0aa296cc8163c3a56475bd 100644
--- a/Source/platform/text/LineEnding.cpp
+++ b/Source/platform/text/LineEnding.cpp
@@ -50,16 +50,16 @@ public:
         : m_buffer(buffer)
     {
     }
-    virtual ~CStringBuffer() { }
+    ~CStringBuffer() override {}
 
-    virtual char* allocate(size_t size) override
+    char* allocate(size_t size) override
     {
         char* ptr;
         m_buffer = CString::newUninitialized(size, ptr);
         return ptr;
     }
 
-    virtual void copy(const CString& source) override
+    void copy(const CString& source) override
     {
         m_buffer = source;
     }
@@ -76,16 +76,16 @@ public:
         : m_buffer(buffer)
     {
     }
-    virtual ~VectorCharAppendBuffer() { }
+    ~VectorCharAppendBuffer() override {}
 
-    virtual char* allocate(size_t size) override
+    char* allocate(size_t size) override
     {
         size_t oldSize = m_buffer.size();
         m_buffer.grow(oldSize + size);
         return m_buffer.data() + oldSize;
     }
 
-    virtual void copy(const CString& source) override
+    void copy(const CString& source) override
     {
         m_buffer.append(source.data(), source.length());
     }