Add a mode flag to the tracing framework.

content/browser/devtools/devtools_tracing_handler.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/devtools/devtools_tracing_handler.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/json/json_writer.h"
 #include "base/location.h"
 #include "base/values.h"
 #include "content/browser/devtools/devtools_http_handler_impl.h"
 #include "content/public/browser/trace_controller.h"
 #include "content/public/browser/trace_subscriber.h"
 
 namespace content {
 
 namespace {
 
 const char kTracingDomain[] = "Tracing";
 
 const char kTracingStartCommand[] = "Tracing.start";
 const char kTracingEndCommand[] = "Tracing.end";
 
 const char kTracingCompleteNotification[] = "Tracing.tracingComplete";
 const char kTracingDataCollected[] = "Tracing.dataCollected";
 
 const char kCategoriesParam[] = "categories";
+const char kTraceModeParam[] = "trace-mode";
 
 }  // namespace
 
 DevToolsTracingHandler::DevToolsTracingHandler()
     : DevToolsBrowserTarget::DomainHandler(kTracingDomain),
       is_running_(false) {
   RegisterCommandHandler(kTracingStartCommand,
                          base::Bind(&DevToolsTracingHandler::OnStart,
                                     base::Unretained(this)));
   RegisterCommandHandler(kTracingEndCommand,
@@ skipping 17 matching lines @@
     SendNotification(kTracingDataCollected, params);
   }
 }
 
 scoped_ptr<DevToolsProtocol::Response>
 DevToolsTracingHandler::OnStart(DevToolsProtocol::Command* command) {
   std::string categories;
   base::DictionaryValue* params = command->params();
   if (params && params->HasKey(kCategoriesParam))
     params->GetString(kCategoriesParam, &categories);
-  TraceController::GetInstance()->BeginTracing(this, categories);
+
+  base::debug::TraceMode mode = base::debug::UNTIL_FULL;
+  if (params && params->HasKey(kTraceModeParam)) {
+    int mode_;
+    params->GetInteger(kTraceModeParam, &mode_);

[pfeldman, 2013/02/20 09:33:38]

You should check for it returning value here.
We also use symbolic names (string enums) for flags like this. You would end up
with switch here, but the protocol will get more stable.

[dsinclair, 2013/02/20 20:36:13]

Done.

I put the conversion in the trace_event_impl.cc code as I've used the same
string names coming from the trace_ui code.

+    mode = static_cast<base::debug::TraceMode>(mode_);
+  }
+
+  TraceController::GetInstance()->BeginTracing(this, categories, mode);
   is_running_ = true;
   return command->SuccessResponse(NULL);
 }
 
 
 scoped_ptr<DevToolsProtocol::Response>
 DevToolsTracingHandler::OnEnd(DevToolsProtocol::Command* command) {
   TraceController::GetInstance()->EndTracingAsync(this);
   return command->SuccessResponse(NULL);
 }
 
 }  // namespace content