[DevTools] [PowerProfiler] Fix for browser crash with active timeline recording for capturing power.

content/browser/devtools/devtools_power_handler.cc

 // Copyright 2014 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_power_handler.h"
 
 #include "base/bind.h"
 #include "base/values.h"
 #include "content/browser/devtools/devtools_protocol_constants.h"
 #include "content/browser/power_profiler/power_profiler_service.h"
 
 namespace content {
 
 DevToolsPowerHandler::DevToolsPowerHandler() {
   RegisterCommandHandler(devtools::Power::start::kName,
                          base::Bind(&DevToolsPowerHandler::OnStart,
                                     base::Unretained(this)));
   RegisterCommandHandler(devtools::Power::end::kName,
                          base::Bind(&DevToolsPowerHandler::OnEnd,
                                     base::Unretained(this)));
   RegisterCommandHandler(devtools::Power::canProfilePower::kName,
                          base::Bind(&DevToolsPowerHandler::OnCanProfilePower,
                                     base::Unretained(this)));
 }
 
 DevToolsPowerHandler::~DevToolsPowerHandler() {
+  PowerProfilerService::GetInstance()->RemoveObserver(this);
 }
 
 void DevToolsPowerHandler::OnPowerEvent(const PowerEventVector& events) {
   base::DictionaryValue* params = new base::DictionaryValue();
   base::ListValue* event_list = new base::ListValue();
 
   std::vector<PowerEvent>::const_iterator iter;
   for (iter = events.begin(); iter != events.end(); ++iter) {
     base::DictionaryValue* event_body = new base::DictionaryValue();
 
@@ skipping 36 matching lines @@
 DevToolsPowerHandler::OnCanProfilePower(
     scoped_refptr<DevToolsProtocol::Command> command) {
   base::DictionaryValue* result = new base::DictionaryValue();
   result->SetBoolean(devtools::kResult,
                      PowerProfilerService::GetInstance()->IsAvailable());
 
   return command->SuccessResponse(result);
 }
 
 }  // namespace content