reapply r70628. It was wrongly blamed for breaking Linux valgrind bots.

net/base/capturing_net_log.cc

Index: net/base/capturing_net_log.cc
diff --git a/net/base/capturing_net_log.cc b/net/base/capturing_net_log.cc
index fccd5aedde3c7df15287a6c00ed4ecda0496230b..c6d3424092d01dfc1f79fda678a0ce5eaef1ec43 100644
--- a/net/base/capturing_net_log.cc
+++ b/net/base/capturing_net_log.cc
@@ -18,7 +18,9 @@ CapturingNetLog::Entry::Entry(EventType type,
 CapturingNetLog::Entry::~Entry() {}
 
 CapturingNetLog::CapturingNetLog(size_t max_num_entries)
-    : last_id_(-1), max_num_entries_(max_num_entries) {
+    : last_id_(-1),
+      max_num_entries_(max_num_entries),
+      log_level_(LOG_ALL_BUT_BYTES) {
 }
 
 CapturingNetLog::~CapturingNetLog() {}
@@ -39,7 +41,8 @@ uint32 CapturingNetLog::NextID() {
 }
 
 NetLog::LogLevel CapturingNetLog::GetLogLevel() const {
-  return LOG_ALL_BUT_BYTES;
+  AutoLock lock(lock_);
+  return log_level_;
 }
 
 void CapturingNetLog::GetEntries(EntryList* entry_list) const {
@@ -52,6 +55,11 @@ void CapturingNetLog::Clear() {
   entries_.clear();
 }
 
+void CapturingNetLog::SetLogLevel(NetLog::LogLevel log_level) {
+  AutoLock lock(lock_);
+  log_level_ = log_level;
+}
+
 CapturingBoundNetLog::CapturingBoundNetLog(const NetLog::Source& source,
                                            CapturingNetLog* net_log)
     : source_(source), capturing_net_log_(net_log) {
@@ -71,4 +79,8 @@ void CapturingBoundNetLog::Clear() {
   capturing_net_log_->Clear();
 }
 
+void CapturingBoundNetLog::SetLogLevel(NetLog::LogLevel log_level) {
+  capturing_net_log_->SetLogLevel(log_level);
+}
+
 }  // namespace net