cc: Don't swap PictureLayerTilingSet on activate.

cc/base/scoped_ptr_vector.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_BASE_SCOPED_PTR_VECTOR_H_
 #define CC_BASE_SCOPED_PTR_VECTOR_H_
 
 #include <algorithm>
 #include <vector>
 
@@ skipping 141 matching lines @@
   void swap(iterator a, iterator b) {
     DCHECK(a < end());
     DCHECK(b < end());
     if (a == end() || b == end() || a == b)
       return;
     typename std::vector<T*>::iterator writable_a = a;
     typename std::vector<T*>::iterator writable_b = b;
     std::swap(*writable_a, *writable_b);
   }
 
+  // This acts like std::remove_if but with one key difference. The values to be
+  // removed to will each appear exactly once at or after the returned iterator,
+  // so that erase(foo.remove_if(P), foo.end()) will not leak or double-free the
+  // pointers in the vector.
+  template <typename Predicate>
+  iterator remove_if(Predicate predicate) {
+    typename std::vector<T*>::iterator it =
+        std::find_if(data_.begin(), data_.end(), predicate);
+    typename std::vector<T*>::iterator end = data_.end();
+    if (it == end)
+      return it;
+    typename std::vector<T*>::iterator result = it;
+    ++it;
+    for (; it != end; ++it) {
+      if (!static_cast<bool>(predicate(*it))) {
+        // Swap here instead of just assign to |result| so that all the
+        // pointers are preserved to be deleted afterward.
+        std::swap(*result, *it);
+        ++result;
+      }
+    }
+    return result;
+  }
+
   template<class Compare>
   inline void sort(Compare comp) {
     std::sort(data_.begin(), data_.end(), comp);
   }
 
   template <class Compare>
   inline void make_heap(Compare comp) {
     std::make_heap(data_.begin(), data_.end(), comp);
   }
 
@@ skipping 19 matching lines @@
 
  private:
   std::vector<T*> data_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedPtrVector);
 };
 
 }  // namespace cc
 
 #endif  // CC_BASE_SCOPED_PTR_VECTOR_H_