Include <algorithm> if you use functions from <algorithm>.

third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 24 matching lines @@
 #include "core/layout/api/LineLayoutInline.h"
 #include "core/layout/api/LineLayoutListMarker.h"
 #include "core/layout/api/LineLayoutRubyRun.h"
 #include "core/layout/line/GlyphOverflow.h"
 #include "core/layout/line/InlineTextBox.h"
 #include "core/layout/line/RootInlineBox.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/InlineFlowBoxPainter.h"
 #include "core/style/ShadowList.h"
 #include "platform/fonts/Font.h"
-
+#include <algorithm>
 #include <math.h>
 
 namespace blink {
 
 struct SameSizeAsInlineFlowBox : public InlineBox {
     void* pointers[5];
     uint32_t bitfields : 23;
 };
 
 static_assert(sizeof(InlineFlowBox) == sizeof(SameSizeAsInlineFlowBox), "InlineFlowBox should stay small");
@@ skipping 1254 matching lines @@
         ASSERT(child->prevOnLine() == prev);
         prev = child;
     }
     ASSERT(prev == m_lastChild);
 #endif
 }
 
 #endif
 
 } // namespace blink