Remove "delete this" pattern from UsbContext completely.

device/usb/usb_context.cc

Index: device/usb/usb_context.cc
diff --git a/device/usb/usb_context.cc b/device/usb/usb_context.cc
index 742b40d4517316f9e0421b1c1701c1e81f216602..ba9779831710d96421e85e8680cd166b601f9556 100644
--- a/device/usb/usb_context.cc
+++ b/device/usb/usb_context.cc
@@ -6,7 +6,7 @@
 
 #include "base/atomicops.h"
 #include "base/logging.h"
-#include "base/threading/platform_thread.h"
+#include "base/threading/simple_thread.h"
 #include "device/usb/usb_error.h"
 #include "third_party/libusb/src/libusb/interrupt.h"
 #include "third_party/libusb/src/libusb/libusb.h"
@@ -16,36 +16,32 @@ namespace device {
 // The UsbEventHandler works around a design flaw in the libusb interface. There
 // is currently no way to signal to libusb that any caller into one of the event
 // handler calls should return without handling any events.
-class UsbContext::UsbEventHandler : public base::PlatformThread::Delegate {
+class UsbContext::UsbEventHandler : public base::SimpleThread {
  public:
   explicit UsbEventHandler(libusb_context* context);
   ~UsbEventHandler() override;
 
-  // base::PlatformThread::Delegate
-  void ThreadMain() override;
+  // base::SimpleThread
+  void Run() override;
 
   void Stop();
 
  private:
   base::subtle::Atomic32 running_;
   libusb_context* context_;
-  base::PlatformThreadHandle thread_handle_;
   DISALLOW_COPY_AND_ASSIGN(UsbEventHandler);
 };
 
 UsbContext::UsbEventHandler::UsbEventHandler(libusb_context* context)
-    : context_(context), thread_handle_(0) {
+    : base::SimpleThread("UsbEventHandler"), context_(context) {
   base::subtle::Release_Store(&running_, 1);
-  bool success = base::PlatformThread::Create(0, this, &thread_handle_);
-  DCHECK(success) << "Failed to create USB IO handling thread.";
 }
 
 UsbContext::UsbEventHandler::~UsbEventHandler() {
   libusb_exit(context_);
 }
 
-void UsbContext::UsbEventHandler::ThreadMain() {
-  base::PlatformThread::SetName("UsbEventHandler");
+void UsbContext::UsbEventHandler::Run() {
   VLOG(1) << "UsbEventHandler started.";
 
   while (base::subtle::Acquire_Load(&running_)) {
@@ -57,24 +53,23 @@ void UsbContext::UsbEventHandler::ThreadMain() {
   }
 
   VLOG(1) << "UsbEventHandler shutting down.";
-  delete this;
 }
 
 void UsbContext::UsbEventHandler::Stop() {
-  base::PlatformThreadHandle thread_handle = thread_handle_;
   base::subtle::Release_Store(&running_, 0);
   libusb_interrupt_handle_event(context_);
-  base::PlatformThread::Join(thread_handle);
 }
 
 UsbContext::UsbContext(PlatformUsbContext context) : context_(context) {
   // Ownership of the PlatformUsbContext is passed to the event handler thread.
-  event_handler_ = new UsbEventHandler(context_);
+  event_handler_.reset(new UsbEventHandler(context_));
+  event_handler_->Start();
 }
 
 UsbContext::~UsbContext() {
   DCHECK(thread_checker_.CalledOnValidThread());
   event_handler_->Stop();
+  event_handler_->Join();
 }
 
 }  // namespace device