Report trace buffer usage as number of events, not only percentage

content/browser/tracing/tracing_controller_impl.h

 // Copyright (c) 2013 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.
 
 #ifndef CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_
 #define CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 25 matching lines @@
                         const base::debug::TraceOptions& trace_options,
                         const EnableMonitoringDoneCallback& callback) override;
   bool DisableMonitoring(
       const DisableMonitoringDoneCallback& callback) override;
   void GetMonitoringStatus(
       bool* out_enabled,
       base::debug::CategoryFilter* out_category_filter,
       base::debug::TraceOptions* out_trace_options) override;
   bool CaptureMonitoringSnapshot(
       const scoped_refptr<TraceDataSink>& sink) override;
-  bool GetTraceBufferPercentFull(
-      const GetTraceBufferPercentFullCallback& callback) override;
+  bool GetTraceBufferUsage(
+      const GetTraceBufferUsageCallback& callback) override;
   bool SetWatchEvent(const std::string& category_name,
                      const std::string& event_name,
                      const WatchEventCallback& callback) override;
   bool CancelWatchEvent() override;
 
   void RegisterTracingUI(TracingUI* tracing_ui);
   void UnregisterTracingUI(TracingUI* tracing_ui);
 
  private:
   typedef std::set<scoped_refptr<TraceMessageFilter> > TraceMessageFilterSet;
@@ skipping 13 matching lines @@
   }
 
   bool can_enable_monitoring() const {
     return !is_monitoring_;
   }
 
   bool can_disable_monitoring() const {
     return is_monitoring_ && !monitoring_data_sink_.get();
   }
 
-  bool can_get_trace_buffer_percent_full() const {
-    return pending_trace_buffer_percent_full_callback_.is_null();
+  bool can_get_trace_buffer_usage() const {
+    return pending_trace_buffer_usage_callback_.is_null();
   }
 
   bool can_cancel_watch_event() const {
     return !watch_event_callback_.is_null();
   }
 
   // Methods for use by TraceMessageFilter.
   void AddTraceMessageFilter(TraceMessageFilter* trace_message_filter);
   void RemoveTraceMessageFilter(TraceMessageFilter* trace_message_filter);
 
@@ skipping 16 matching lines @@
       const std::vector<std::string>& known_category_groups);
 
 #if defined(OS_CHROMEOS) || defined(OS_WIN)
   void OnEndSystemTracingAcked(
       const scoped_refptr<base::RefCountedString>& events_str_ptr);
 #endif
 
   void OnCaptureMonitoringSnapshotAcked(
       TraceMessageFilter* trace_message_filter);
 
-  void OnTraceBufferPercentFullReply(
-      TraceMessageFilter* trace_message_filter,
-      float percent_full);
+  void OnTraceBufferUsageReply(TraceMessageFilter* trace_message_filter,
+                               size_t event_capacity,
+                               size_t event_count);
 
   void OnWatchEventMatched();
 
   void SetEnabledOnFileThread(
       const base::debug::CategoryFilter& category_filter,
       int mode,
       const base::debug::TraceOptions& trace_options,
       const base::Closure& callback);
   void SetDisabledOnFileThread(const base::Closure& callback);
   void OnEnableRecordingDone(const base::debug::CategoryFilter& category_filter,
                              const base::debug::TraceOptions& trace_options,
                              const EnableRecordingDoneCallback& callback);
   void OnDisableRecordingDone();
   void OnEnableMonitoringDone(
       const base::debug::CategoryFilter& category_filter,
       const base::debug::TraceOptions& trace_options,
       const EnableMonitoringDoneCallback& callback);
   void OnDisableMonitoringDone(const DisableMonitoringDoneCallback& callback);
 
   void OnMonitoringStateChanged(bool is_monitoring);
 
   TraceMessageFilterSet trace_message_filters_;
 
   // Pending acks for DisableRecording.
   int pending_disable_recording_ack_count_;
   TraceMessageFilterSet pending_disable_recording_filters_;
   // Pending acks for CaptureMonitoringSnapshot.
   int pending_capture_monitoring_snapshot_ack_count_;
   TraceMessageFilterSet pending_capture_monitoring_filters_;
-  // Pending acks for GetTraceBufferPercentFull.
-  int pending_trace_buffer_percent_full_ack_count_;
-  TraceMessageFilterSet pending_trace_buffer_percent_full_filters_;
-  float maximum_trace_buffer_percent_full_;
+  // Pending acks for GetTraceBufferUsage.
+  int pending_trace_buffer_usage_ack_count_;
+  TraceMessageFilterSet pending_trace_buffer_usage_filters_;
+  float maximum_trace_buffer_usage_;
+  size_t approximate_event_count_;
 
 #if defined(OS_CHROMEOS) || defined(OS_WIN)
   bool is_system_tracing_;
 #endif
   bool is_recording_;
   bool is_monitoring_;
   base::debug::TraceOptions trace_options_;
 
   GetCategoriesDoneCallback pending_get_categories_done_callback_;
-  GetTraceBufferPercentFullCallback pending_trace_buffer_percent_full_callback_;
+  GetTraceBufferUsageCallback pending_trace_buffer_usage_callback_;
 
   std::string watch_category_name_;
   std::string watch_event_name_;
   WatchEventCallback watch_event_callback_;
 
   std::set<std::string> known_category_groups_;
   std::set<TracingUI*> tracing_uis_;
   scoped_refptr<TraceDataSink> trace_data_sink_;
   scoped_refptr<TraceDataSink> monitoring_data_sink_;
   DISALLOW_COPY_AND_ASSIGN(TracingControllerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_