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

components/tracing/tracing_messages.h

 // Copyright (c) 2012 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.
 
 // Multiply-included message header, no traditional include guard.
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/debug/trace_event_impl.h"
 #include "base/sync_socket.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
 #include "ipc/ipc_platform_file.h"
 
 #define IPC_MESSAGE_START TracingMsgStart
 
+IPC_STRUCT_TRAITS_BEGIN(base::debug::TraceLogStatus)
+IPC_STRUCT_TRAITS_MEMBER(event_capacity)
+IPC_STRUCT_TRAITS_MEMBER(event_count)
+IPC_STRUCT_TRAITS_END()
+
 // Sent to all child processes to enable trace event recording.
 IPC_MESSAGE_CONTROL3(TracingMsg_BeginTracing,
                      std::string /*  category_filter_str */,
                      base::TimeTicks /* browser_time */,
                      std::string /* base::debug::TraceOptions */)
 
 // Sent to all child processes to disable trace event recording.
 IPC_MESSAGE_CONTROL0(TracingMsg_EndTracing)
 
 // Sent to all child processes to start monitoring.
 IPC_MESSAGE_CONTROL3(TracingMsg_EnableMonitoring,
                      std::string /*  category_filter_str */,
                      base::TimeTicks /* browser_time */,
                      std::string /* base::debug::TraceOptions */)
 
 // Sent to all child processes to stop monitoring.
 IPC_MESSAGE_CONTROL0(TracingMsg_DisableMonitoring)
 
 // Sent to all child processes to capture the current monitorint snapshot.
 IPC_MESSAGE_CONTROL0(TracingMsg_CaptureMonitoringSnapshot)
 
 // Sent to all child processes to get trace buffer fullness.
-IPC_MESSAGE_CONTROL0(TracingMsg_GetTraceBufferPercentFull)
+IPC_MESSAGE_CONTROL0(TracingMsg_GetTraceLogStatus)
 
 // Sent to all child processes to set watch event.
 IPC_MESSAGE_CONTROL2(TracingMsg_SetWatchEvent,
                      std::string /* category_name */,
                      std::string /* event_name */)
 
 // Sent to all child processes to clear watch event.
 IPC_MESSAGE_CONTROL0(TracingMsg_CancelWatchEvent)
 
 // Sent everytime when a watch event is matched.
@@ skipping 11 matching lines @@
 
 // Child processes send back trace data in JSON chunks.
 IPC_MESSAGE_CONTROL1(TracingHostMsg_TraceDataCollected,
                      std::string /*json trace data*/)
 
 // Child processes send back trace data of the current monitoring
 // in JSON chunks.
 IPC_MESSAGE_CONTROL1(TracingHostMsg_MonitoringTraceDataCollected,
                      std::string /*json trace data*/)
 
-// Reply to TracingMsg_GetTraceBufferPercentFull.
-IPC_MESSAGE_CONTROL1(TracingHostMsg_TraceBufferPercentFullReply,
-                     float /*trace buffer percent full*/)
-
+// Reply to TracingMsg_GetTraceLogStatus.
+IPC_MESSAGE_CONTROL1(TracingHostMsg_TraceLogStatusReply,
+                     base::debug::TraceLogStatus /*status of the trace log*/)