Anti-DDoS enhancements: Log to net log, UMA stats, improved policy.

chrome/browser/net/passive_log_collector.h

Index: chrome/browser/net/passive_log_collector.h
diff --git a/chrome/browser/net/passive_log_collector.h b/chrome/browser/net/passive_log_collector.h
index d2090319c5d4b42e15a5112afa2124273c7de090..2687c66eb5b8d558e0f913d9cf054872d65a5bd4 100644
--- a/chrome/browser/net/passive_log_collector.h
+++ b/chrome/browser/net/passive_log_collector.h
@@ -341,6 +341,19 @@ class PassiveLogCollector : public ChromeNetLog::ThreadSafeObserver {
     DISALLOW_COPY_AND_ASSIGN(HttpStreamJobTracker);
   };
 
+  class ExponentialBackoffThrottlingTracker : public SourceTracker {
+   public:
+    static const size_t kMaxNumSources;
+    static const size_t kMaxGraveyardSize;
+
+    explicit ExponentialBackoffThrottlingTracker(PassiveLogCollector* parent);
+
+   private:
+    virtual Action DoAddEntry(const ChromeNetLog::Entry& entry,
+                              SourceInfo* out_info);
+    DISALLOW_COPY_AND_ASSIGN(ExponentialBackoffThrottlingTracker);
+  };
+
 
   PassiveLogCollector();
   virtual ~PassiveLogCollector();
@@ -381,6 +394,7 @@ class PassiveLogCollector : public ChromeNetLog::ThreadSafeObserver {
   DiskCacheEntryTracker disk_cache_entry_tracker_;
   MemCacheEntryTracker mem_cache_entry_tracker_;
   HttpStreamJobTracker http_stream_job_tracker_;
+  ExponentialBackoffThrottlingTracker exponential_backoff_throttling_tracker_;
 
   // This array maps each NetLog::SourceType to one of the tracker instances
   // defined above. Use of this array avoid duplicating the list of trackers