Remove ChromeNetLog dependency from content/browser/debugger.

Add Observer concept to net::NetLog.

Use net::NetLog::Observer in ChromeNetLog.

Remove ChromeNetLog dependency in content/browser/debugger.

Forked from http://codereview.chromium.org/7310029/ to finish Jói's
patch.

BUG=84078
TEST=existing

Review URL: http://codereview.chromium.org/7468019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@94196 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 52 insertions, 0 deletions

diff --git a/net/base/net_log.h b/net/base/net_log.h
index 39fa915..051ba93 100644
--- a/net/base/net_log.h
+++ b/net/base/net_log.h
@@ -104,6 +104,50 @@ class NET_API NetLog {
     LOG_BASIC,
   };
 
+  // An observer, that must ensure its own thread safety, for events
+  // being added to a NetLog.
+  class ThreadSafeObserver {
+   public:
+    // Constructs an observer that wants to see network events, with
+    // the specified minimum event granularity.  A ThreadSafeObserver can only
+    // observe a single NetLog at a time.
+    //
+    // Typical observers should specify LOG_BASIC.
+    //
+    // Observers that need to see the full granularity of events can
+    // specify LOG_ALL. However doing so will have performance consequences.
+    //
+    // Observers will be called on the same thread an entry is added on,
+    // and are responsible for ensuring their own thread safety.
+    explicit ThreadSafeObserver(LogLevel log_level);
+    virtual ~ThreadSafeObserver();
+
+    // Returns the minimum log level for events this observer wants to
+    // receive.
+    LogLevel log_level() const;
+
+    // This method will be called on the thread that the event occurs on.  It
+    // is the responsibility of the observer to handle it in a thread safe
+    // manner.
+    //
+    // It is illegal for an Observer to call any NetLog or
+    // NetLog::Observer functions in response to a call to OnAddEntry.
+    virtual void OnAddEntry(EventType type,
+                            const base::TimeTicks& time,
+                            const Source& source,
+                            EventPhase phase,
+                            EventParameters* params) = 0;
+
+   protected:
+    // Subclasses should only ever modify this if they somehow
+    // collaborate with concrete implementations of NetLog to enable
+    // modification.
+    LogLevel log_level_;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(ThreadSafeObserver);
+  };
+
   NetLog() {}
   virtual ~NetLog() {}
 
@@ -130,6 +174,14 @@ class NET_API NetLog {
   // and saving expensive log entries.
   virtual LogLevel GetLogLevel() const = 0;
 
+  // Adds an observer. Each observer may be added only once and must
+  // be removed via |RemoveObserver()| before this object goes out of
+  // scope.
+  virtual void AddThreadSafeObserver(ThreadSafeObserver* observer) = 0;
+
+  // Removes an observer.
+  virtual void RemoveThreadSafeObserver(ThreadSafeObserver* observer) = 0;
+
   // Converts a time to the string format that the NetLog uses to represent
   // times.  Strings are used since integers may overflow.
   static std::string TickCountToString(const base::TimeTicks& time);