Add HTML parser UMA for rewinds and chunk queue statistics.

third_party/WebKit/Source/core/html/parser/ParsedChunkQueue.cpp

 // Copyright 2015 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.
 
 #include "core/html/parser/ParsedChunkQueue.h"
 
+#include <algorithm>
 #include <memory>
 
 namespace blink {
 
 ParsedChunkQueue::ParsedChunkQueue()
 {
 }
 
 ParsedChunkQueue::~ParsedChunkQueue()
 {
 }
 
 bool ParsedChunkQueue::enqueue(std::unique_ptr<HTMLDocumentParser::ParsedChunk> chunk)
 {
     MutexLocker locker(m_mutex);
 
+    m_pendingTokenCount += chunk->tokens->size();
+    m_peakPendingTokenCount = std::max(m_peakPendingTokenCount, m_pendingTokenCount);
+
     bool wasEmpty = m_pendingChunks.isEmpty();
     m_pendingChunks.append(std::move(chunk));
+    m_peakPendingChunkCount = std::max(m_peakPendingChunkCount, m_pendingChunks.size());
+
     return wasEmpty;
 }
 
 void ParsedChunkQueue::clear()
 {
     MutexLocker locker(m_mutex);
 
+    m_pendingTokenCount = 0;
     m_pendingChunks.clear();
 }
 
 void ParsedChunkQueue::takeAll(Vector<std::unique_ptr<HTMLDocumentParser::ParsedChunk>>& vector)
 {
     MutexLocker locker(m_mutex);
 
     ASSERT(vector.isEmpty());
     m_pendingChunks.swap(vector);
 }
 
+size_t ParsedChunkQueue::peakPendingChunkCount()
+{
+    MutexLocker locker(m_mutex);
+    return m_peakPendingChunkCount;
+}
+
+size_t ParsedChunkQueue::peakPendingTokenCount()
+{
+    MutexLocker locker(m_mutex);
+    return m_peakPendingTokenCount;
+}
+
 } // namespace blink