Update tracing framework to optionally use a ringbuffer.

content/browser/tracing/trace_controller_impl.cc

 // 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.
 
 #include "content/browser/tracing/trace_controller_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/string_number_conversions.h"
@@ skipping 119 matching lines @@
 
   // Enable tracing
   TraceLog::GetInstance()->SetEnabled(included_categories, excluded_categories);
   OnTracingBegan(subscriber);
 
   return true;
 }
 
 bool TraceControllerImpl::BeginTracing(TraceSubscriber* subscriber,
                                        const std::string& categories) {
+  return BeginTracing(subscriber, categories, false);
+}
+
+bool TraceControllerImpl::BeginTracing(TraceSubscriber* subscriber,
+                                       const std::string& categories,
+                                       bool continuous_tracing) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (!can_begin_tracing(subscriber))
     return false;
 
   // Enable tracing
   TraceLog::GetInstance()->SetEnabled(categories);
+  TraceLog::GetInstance()->SetContinuousTracing(continuous_tracing);
 
   OnTracingBegan(subscriber);
 
   return true;
 }
 
 bool TraceControllerImpl::EndTracingAsync(TraceSubscriber* subscriber) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (!can_end_tracing() || subscriber != subscriber_)
@@ skipping 97 matching lines @@
 void TraceControllerImpl::AddFilter(TraceMessageFilter* filter) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
         base::Bind(&TraceControllerImpl::AddFilter, base::Unretained(this),
                    make_scoped_refptr(filter)));
     return;
   }
 
   filters_.insert(filter);
   if (is_tracing_enabled()) {
-    filter->SendBeginTracing(included_categories_, excluded_categories_);
+    filter->SendBeginTracing(included_categories_, excluded_categories_,
+                             continuous_tracing_);
     if (!watch_category_.empty())
       filter->SendSetWatchEvent(watch_category_, watch_name_);
   }
 }
 
 void TraceControllerImpl::RemoveFilter(TraceMessageFilter* filter) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
         base::Bind(&TraceControllerImpl::RemoveFilter, base::Unretained(this),
                    make_scoped_refptr(filter)));
     return;
   }
 
   filters_.erase(filter);
 }
 
 void TraceControllerImpl::OnTracingBegan(TraceSubscriber* subscriber) {
   is_tracing_ = true;
 
   subscriber_ = subscriber;
 
   TraceLog::GetInstance()->GetEnabledTraceCategories(&included_categories_,
                                                      &excluded_categories_);
+  continuous_tracing_ = TraceLog::GetInstance()->GetContinuousTracing();
+
   // Notify all child processes.
   for (FilterMap::iterator it = filters_.begin(); it != filters_.end(); ++it) {
-    it->get()->SendBeginTracing(included_categories_, excluded_categories_);
+    it->get()->SendBeginTracing(included_categories_, excluded_categories_,
+                                continuous_tracing_);
   }
 }
 
 void TraceControllerImpl::OnEndTracingAck(
     const std::vector<std::string>& known_categories) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
         base::Bind(&TraceControllerImpl::OnEndTracingAck,
                    base::Unretained(this), known_categories));
     return;
@@ skipping 104 matching lines @@
     // The last ack represents local trace, so we need to ack it now. Note that
     // this code only executes if there were child processes.
     float bpf = TraceLog::GetInstance()->GetBufferPercentFull();
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
         base::Bind(&TraceControllerImpl::OnTraceBufferPercentFullReply,
                    base::Unretained(this), bpf));
   }
 }
 
 }  // namespace content