[WebView] Remove Bind on an ownerless refcounted instance.

CL https://chromium-review.googlesource.com/1144813 prevents ownerless
RefCounted receiver on base::Bind.

The class AwLoginDelegate does a PostTask in its constructor using
'this'. This violate a CHECK(...).

The CL makes the constructor private. It introduces the static method
Create(). It wraps the raw pointer in the scoped_refptr class first and
THEN call base::Bind on it.

Bug: 870479
Change-Id: Iebbd51e3136fb1a52962b8f5a0951f6b89145742
Reviewed-on: https://chromium-review.googlesource.com/1179758Reviewed-by: Richard Coles <torne@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584092}

android_webview/browser/aw_content_browser_client.cc

@@ -714,9 +714,9 @@ AwContentBrowserClient::CreateLoginDelegate(
     scoped_refptr<net::HttpResponseHeaders> response_headers,
     bool first_auth_attempt,
     LoginAuthRequiredCallback auth_required_callback) {
-  return base::MakeRefCounted<AwLoginDelegate>(
-      auth_info, web_contents_getter, first_auth_attempt,
-      std::move(auth_required_callback));
+  return AwLoginDelegate::Create(auth_info, web_contents_getter,
+                                 first_auth_attempt,
+                                 std::move(auth_required_callback));
 }
 
 bool AwContentBrowserClient::HandleExternalProtocol(

android_webview/browser/aw_login_delegate.cc

@@ -20,19 +20,27 @@ using content::WebContents;
 
 namespace android_webview {
 
-AwLoginDelegate::AwLoginDelegate(
+// static
+scoped_refptr<AwLoginDelegate> AwLoginDelegate::Create(
     net::AuthChallengeInfo* auth_info,
     content::ResourceRequestInfo::WebContentsGetter web_contents_getter,
     bool first_auth_attempt,
-    LoginAuthRequiredCallback auth_required_callback)
-    : auth_info_(auth_info),
-      auth_required_callback_(std::move(auth_required_callback)) {
+    LoginAuthRequiredCallback auth_required_callback) {
+  scoped_refptr<AwLoginDelegate> instance(
+      new AwLoginDelegate(auth_info, std::move(auth_required_callback)));
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
-      base::BindOnce(&AwLoginDelegate::HandleHttpAuthRequestOnUIThread, this,
-                     first_auth_attempt, web_contents_getter));
+      base::BindOnce(&AwLoginDelegate::HandleHttpAuthRequestOnUIThread,
+                     instance, first_auth_attempt, web_contents_getter));
+  return instance;
 }
 
+AwLoginDelegate::AwLoginDelegate(
+    net::AuthChallengeInfo* auth_info,
+    LoginAuthRequiredCallback auth_required_callback)
+    : auth_info_(auth_info),
+      auth_required_callback_(std::move(auth_required_callback)) {}
+
 AwLoginDelegate::~AwLoginDelegate() {
   // The Auth handler holds a ref count back on |this| object, so it should be
   // impossible to reach here while this object still owns an auth handler.

android_webview/browser/aw_login_delegate.h

@@ -24,7 +24,7 @@ namespace android_webview {
 
 class AwLoginDelegate : public content::LoginDelegate {
  public:
-  AwLoginDelegate(
+  static scoped_refptr<AwLoginDelegate> Create(
       net::AuthChallengeInfo* auth_info,
       content::ResourceRequestInfo::WebContentsGetter web_contents_getter,
       bool first_auth_attempt,
@@ -38,6 +38,8 @@ class AwLoginDelegate : public content::LoginDelegate {
   void OnRequestCancelled() override;
 
  private:
+  AwLoginDelegate(net::AuthChallengeInfo* auth_info,
+                  LoginAuthRequiredCallback auth_required_callback);
   ~AwLoginDelegate() override;
   void HandleHttpAuthRequestOnUIThread(
       bool first_auth_attempt,