Change ChooserController ownership model

chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc

Index: chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc
diff --git a/chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc b/chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc
index bb653096282127a0834a23019250b6b20dbb1b07..b1962b9af9884a9abbb66754b9d25faf4a0776ea 100644
--- a/chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc
+++ b/chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc
@@ -11,11 +11,15 @@
 ChromeExtensionBluetoothChooser::ChromeExtensionBluetoothChooser(
     content::RenderFrameHost* frame,
     const content::BluetoothChooser::EventHandler& event_handler) {
-  bluetooth_chooser_controller_.reset(
+  std::unique_ptr<BluetoothChooserController> bluetooth_chooser_controller(
       new BluetoothChooserController(frame, event_handler));
+  // Since ChromeExtensionBluetoothChooser object is destroyed before the

[msw, 2016/06/22 18:23:17]

I can't really reason about the lifetime of the dialog's views in relation to
this ChromeExtensionBluetoothChooser instance (owned by
content/browser/bluetooth/bluetooth_device_chooser_controller.cc). How did you
come to this assessment and can you really assert that the dialog never closes
(tears down its view hierarchy or similar cocoa structures) earlier than this
object in all cases?

[juncai, 2016/06/22 22:41:20]

When user makes a selection or cancels, it will call
ChooserContentView::Accept(), or Cancel() before bubble/dialog closes, and that
will call ChooserController::Select(), or Cancel(). For bluetooth, it will call
event_handler_.Run():
https://cs.chromium.org/chromium/src/chrome/browser/ui/bluetooth/bluetooth_ch...
and that will call:
https://cs.chromium.org/chromium/src/content/browser/bluetooth/bluetooth_devi...
and it frees the |chooser_| at:
https://cs.chromium.org/chromium/src/content/browser/bluetooth/bluetooth_devi...

So I guess this object is destroyed before chooser view is destroyed.

[msw, 2016/06/22 23:13:37]

Acknowledged.

+  // view object which owns |bluetooth_chooser_controller_| when the chooser
+  // bubble/dialog closes, it is safe to store and use the raw pointer here.
+  bluetooth_chooser_controller_ = bluetooth_chooser_controller.get();
   chooser_dialog_.reset(new ChromeExtensionChooserDialog(
       content::WebContents::FromRenderFrameHost(frame)));
-  chooser_dialog_->ShowDialog(bluetooth_chooser_controller_.get());
+  chooser_dialog_->ShowDialog(std::move(bluetooth_chooser_controller));
 }
 
 ChromeExtensionBluetoothChooser::~ChromeExtensionBluetoothChooser() {}