[DevTools] Fix browser crash when instantiating AbdTargetUIHandler for incognito profile.

chrome/browser/devtools/devtools_targets_ui.cc

 // Copyright 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.
 
 #include "chrome/browser/devtools/devtools_targets_ui.h"
 
 #include "base/location.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
@@ skipping 275 matching lines @@
       scoped_refptr<DevToolsAndroidBridge::RemoteBrowser> > RemoteBrowsers;
   RemoteBrowsers remote_browsers_;
 };
 
 AdbTargetsUIHandler::AdbTargetsUIHandler(const Callback& callback,
                                          Profile* profile)
     : DevToolsTargetsUIHandler(kTargetSourceRemote, callback),
       profile_(profile),
       android_bridge_(
           DevToolsAndroidBridge::Factory::GetForProfile(profile_)) {
-  DCHECK(android_bridge_);
-  android_bridge_->AddDeviceListListener(this);
+  if (android_bridge_)
+    android_bridge_->AddDeviceListListener(this);
 }
 
 AdbTargetsUIHandler::~AdbTargetsUIHandler() {
-  android_bridge_->RemoveDeviceListListener(this);
+  if (android_bridge_)
+    android_bridge_->RemoveDeviceListListener(this);
 }
 
 void AdbTargetsUIHandler::Open(const std::string& browser_id,
                                const std::string& url) {
   RemoteBrowsers::iterator it = remote_browsers_.find(browser_id);
-  if (it != remote_browsers_.end())
+  if (it != remote_browsers_.end() && android_bridge_)
     android_bridge_->OpenRemotePage(it->second, url);
 }
 
 scoped_refptr<content::DevToolsAgentHost>
 AdbTargetsUIHandler::GetBrowserAgentHost(
     const std::string& browser_id) {
   RemoteBrowsers::iterator it = remote_browsers_.find(browser_id);
-  if (it == remote_browsers_.end())
-    return NULL;
+  if (it == remote_browsers_.end() || !android_bridge_)
+    return nullptr;
 
   return android_bridge_->GetBrowserAgentHost(it->second);
 }
 
 void AdbTargetsUIHandler::DeviceListChanged(
     const DevToolsAndroidBridge::RemoteDevices& devices) {
   remote_browsers_.clear();
   STLDeleteValues(&targets_);
+  if (!android_bridge_)
+    return;
 
   base::ListValue device_list;
   for (DevToolsAndroidBridge::RemoteDevices::const_iterator dit =
       devices.begin(); dit != devices.end(); ++dit) {
     DevToolsAndroidBridge::RemoteDevice* device = dit->get();
     base::DictionaryValue* device_data = new base::DictionaryValue();
     device_data->SetString(kAdbModelField, device->model());
     device_data->SetString(kAdbSerialField, device->serial());
     device_data->SetBoolean(kAdbConnectedField, device->is_connected());
     std::string device_id = base::StringPrintf(
@@ skipping 153 matching lines @@
     device_status_dict->SetString(kPortForwardingBrowserId,
                                   sit->first->GetId());
 
     std::string device_id = base::StringPrintf(
         kAdbDeviceIdFormat,
         sit->first->serial().c_str());
     result.Set(device_id, device_status_dict);
   }
   callback_.Run(result);
 }