Fix WeakPtrFactory ordering problems in src/tools

Cleaning up weak_ptr_factory destruction order in "src/tools" module.
WeakPtrFactory should remain the last member so it'll be destroyed and
invalidate its weak pointers before any other members are destroyed.

BUG=303818

Review URL: https://codereview.chromium.org/555093002

Cr-Commit-Position: refs/heads/master@{#294117}

3 files changed, 18 insertions, 8 deletions

diff --git a/tools/android/forwarder2/device_controller.cc b/tools/android/forwarder2/device_controller.cc
index 7a4c0ad..a4cb9c7 100644
--- a/tools/android/forwarder2/device_controller.cc
+++ b/tools/android/forwarder2/device_controller.cc
@@ -47,10 +47,10 @@ void DeviceController::Start() {
 
 DeviceController::DeviceController(scoped_ptr<Socket> host_socket,
                                    int exit_notifier_fd)
-    : weak_ptr_factory_(this),
-      host_socket_(host_socket.Pass()),
+    : host_socket_(host_socket.Pass()),
       exit_notifier_fd_(exit_notifier_fd),
-      construction_task_runner_(base::MessageLoopProxy::current()) {
+      construction_task_runner_(base::MessageLoopProxy::current()),
+      weak_ptr_factory_(this) {
   host_socket_->AddEventFd(exit_notifier_fd);
 }
 
diff --git a/tools/android/forwarder2/device_controller.h b/tools/android/forwarder2/device_controller.h
index b1441d8..567a08d 100644
--- a/tools/android/forwarder2/device_controller.h
+++ b/tools/android/forwarder2/device_controller.h
@@ -49,7 +49,6 @@ class DeviceController {
       const base::WeakPtr<DeviceController>& device_controller_ptr,
       scoped_ptr<DeviceListener> device_listener);
 
-  base::WeakPtrFactory<DeviceController> weak_ptr_factory_;
   const scoped_ptr<Socket> host_socket_;
   // Used to notify the controller to exit.
   const int exit_notifier_fd_;
@@ -58,6 +57,12 @@ class DeviceController {
   const scoped_refptr<base::SingleThreadTaskRunner> construction_task_runner_;
   ListenersMap listeners_;
 
+  //WeakPtrFactory's documentation says:
+  // Member variables should appear before the WeakPtrFactory, to ensure
+  // that any WeakPtrs to Controller are invalidated before its members
+  // variable's destructors are executed, rendering them invalid.
+  base::WeakPtrFactory<DeviceController> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(DeviceController);
 };
 
diff --git a/tools/android/forwarder2/self_deleter_helper.h b/tools/android/forwarder2/self_deleter_helper.h
index a9d7498..d96903d 100644
--- a/tools/android/forwarder2/self_deleter_helper.h
+++ b/tools/android/forwarder2/self_deleter_helper.h
@@ -99,10 +99,10 @@ class SelfDeleterHelper {
 
   SelfDeleterHelper(T* self_deleting_object,
                     const DeletionCallback& deletion_callback)
-      : weak_ptr_factory_(this),
-        construction_runner_(base::MessageLoopProxy::current()),
+      : construction_runner_(base::MessageLoopProxy::current()),
         self_deleting_object_(self_deleting_object),
-        deletion_callback_(deletion_callback) {
+        deletion_callback_(deletion_callback),
+        weak_ptr_factory_(this) {
   }
 
   ~SelfDeleterHelper() {
@@ -123,11 +123,16 @@ class SelfDeleterHelper {
     deletion_callback_.Run(make_scoped_ptr(self_deleting_object_));
   }
 
-  base::WeakPtrFactory<SelfDeleterHelper<T> > weak_ptr_factory_;
   const scoped_refptr<base::SingleThreadTaskRunner> construction_runner_;
   T* const self_deleting_object_;
   const DeletionCallback deletion_callback_;
 
+  //WeakPtrFactory's documentation says:
+  // Member variables should appear before the WeakPtrFactory, to ensure
+  // that any WeakPtrs to Controller are invalidated before its members
+  // variable's destructors are executed, rendering them invalid.
+  base::WeakPtrFactory<SelfDeleterHelper<T> > weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(SelfDeleterHelper);
 };