Merge pull request #175 from Quuxplusone/suggest-override

Fix -Wsuggest-override warnings from Clang

snappy.cc

@@ -1888,16 +1888,16 @@ class SnappyIOVecReader : public Source {
     if (total_size > 0 && curr_size_remaining_ == 0) Advance();
   }
 
-  ~SnappyIOVecReader() = default;
+  ~SnappyIOVecReader() override = default;
 
-  size_t Available() const { return total_size_remaining_; }
+  size_t Available() const override { return total_size_remaining_; }
 
-  const char* Peek(size_t* len) {
+  const char* Peek(size_t* len) override {
     *len = curr_size_remaining_;
     return curr_pos_;
   }
 
-  void Skip(size_t n) {
+  void Skip(size_t n) override {
     while (n >= curr_size_remaining_ && n > 0) {
       n -= curr_size_remaining_;
       Advance();
@@ -2535,7 +2535,6 @@ bool SnappyScatteredWriter<Allocator>::SlowAppendFromSelf(size_t offset,
 class SnappySinkAllocator {
  public:
   explicit SnappySinkAllocator(Sink* dest) : dest_(dest) {}
-  ~SnappySinkAllocator() {}
 
   char* Allocate(int size) {
     Datablock block(new char[size], size);