Chrome Cleaner UI: Use BrowserThread's DeleteOnIOThread for ChromePromptImpl

chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc

Index: chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc
diff --git a/chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc b/chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc
index ce4ed9d4d5c3be7297915c060fdb5251d989be34..aa07a4c77965d9cc551d4060dad846d32d4f6ce7 100644
--- a/chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc
+++ b/chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc
@@ -21,7 +21,6 @@
 #include "components/chrome_cleaner/public/constants/constants.h"
 #include "components/chrome_cleaner/public/interfaces/chrome_prompt.mojom.h"
 #include "components/version_info/version_info.h"
-#include "content/public/browser/browser_thread.h"
 #include "mojo/edk/embedder/connection_params.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/embedder/outgoing_broker_client_invitation.h"
@@ -41,13 +40,6 @@ namespace {
 // tests.
 ChromeCleanerRunnerTestDelegate* g_test_delegate = nullptr;
 
-void ReleaseChromePromptImpl(
-    std::unique_ptr<ChromePromptImpl> chrome_prompt_impl) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK(chrome_prompt_impl);
-  chrome_prompt_impl.reset();
-}
-
 }  // namespace
 
 // static
@@ -192,24 +184,18 @@ ChromeCleanerRunner::LaunchAndWaitForExitOnBackgroundThread() {
   return {false, kBadProcessExitCode};
 }
 
-ChromeCleanerRunner::~ChromeCleanerRunner() {
-  if (chrome_prompt_impl_) {
-    BrowserThread::GetTaskRunnerForThread(BrowserThread::IO)
-        ->PostTask(FROM_HERE, base::Bind(&ReleaseChromePromptImpl,
-                                         base::Passed(&chrome_prompt_impl_)));
-  }
-}
+ChromeCleanerRunner::~ChromeCleanerRunner() = default;

[csharp, 2017/05/25 20:39:19]

nit: Since this is just default now, you can just do it in the header.

[alito, 2017/05/26 15:29:39]

As discussed, this should be here according to Chromium's C++ Dos and Don'ts
doc.

 
 void ChromeCleanerRunner::CreateChromePromptImpl(
     ChromePromptRequest chrome_prompt_request) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(!chrome_prompt_impl_);
 
-  chrome_prompt_impl_ = base::MakeUnique<ChromePromptImpl>(
+  chrome_prompt_impl_.reset(new ChromePromptImpl(

[Joe Mason, 2017/05/25 20:41:13]

Nit: perhaps a comment explaining why you can't use MakeUnique here, since
people have mentioned giving bare new extra scrutiny.

[alito, 2017/05/26 15:29:39]

Done.

       std::move(chrome_prompt_request),
       base::Bind(&ChromeCleanerRunner::OnConnectionClosed,
                  base::RetainedRef(this)),
-      base::Bind(&ChromeCleanerRunner::OnPromptUser, base::RetainedRef(this)));
+      base::Bind(&ChromeCleanerRunner::OnPromptUser, base::RetainedRef(this))));
 }
 
 void ChromeCleanerRunner::OnPromptUser(