Fix a crash in PasswordGenerationPopupControllerImpl caused by double deletion.

The flow of the crash
- PasswordManager::OnGeneratedPasswordAccepted is called when a generated password is accepted.
- It can bring up the "Update Password?" bubble
- Focus lost event is happening, the dropdown is closed, the controller is destroyed.
- PasswordManager::OnGeneratedPasswordAccepted finishes.
- PasswordGenerationPopupControllerImpl tries to hide the UI again but everything is gone already.

Bug: 995321
Change-Id: I791c969ea6af1b6fc305219a5c22d49424ab38ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1762214Reviewed-by: Ioana Pandele <ioanap@chromium.org>
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688556}

chrome/browser/ui/passwords/password_generation_popup_controller_impl.cc

@@ -193,10 +193,13 @@ void PasswordGenerationPopupControllerImpl::PasswordAccepted() {
   if (state_ != kOfferGeneration)
     return;
 
-  driver_->GetPasswordManager()->OnGeneratedPasswordAccepted(
-      driver_.get(), form_.form_data, generation_element_id_,
+  base::WeakPtr<PasswordGenerationPopupControllerImpl> weak_this = GetWeakPtr();
+  driver_->GeneratedPasswordAccepted(form_.form_data, generation_element_id_,
                                      current_password_);
-  Hide();
+  // |this| can be destroyed here because GeneratedPasswordAccepted pops up
+  // another UI and generates some event to close the dropdown.
+  if (weak_this)
+    weak_this->Hide();
 }
 
 void PasswordGenerationPopupControllerImpl::Show(GenerationUIState state) {

chrome/browser/ui/passwords/password_generation_popup_controller_impl_unittest.cc

@@ -10,20 +10,33 @@
 #include "components/autofill/core/common/password_generation_util.h"
 #include "components/password_manager/core/browser/stub_password_manager_driver.h"
 #include "content/public/browser/web_contents.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 namespace {
 
+using ::testing::_;
+
+class MockPasswordManagerDriver
+    : public password_manager::StubPasswordManagerDriver {
+ public:
+  MOCK_METHOD1(GeneratedPasswordAccepted, void(const base::string16&));
+  MOCK_METHOD3(GeneratedPasswordAccepted,
+               void(const autofill::FormData&,
+                    uint32_t,
+                    const base::string16&));
+};
+
 class PasswordGenerationPopupControllerImplTest
     : public ChromeRenderViewHostTestHarness {
  public:
-  std::unique_ptr<password_manager::PasswordManagerDriver> CreateDriver();
+  std::unique_ptr<MockPasswordManagerDriver> CreateDriver();
 };
 
-std::unique_ptr<password_manager::PasswordManagerDriver>
+std::unique_ptr<MockPasswordManagerDriver>
 PasswordGenerationPopupControllerImplTest::CreateDriver() {
-  return std::make_unique<password_manager::StubPasswordManagerDriver>();
+  return std::make_unique<MockPasswordManagerDriver>();
 }
 
 TEST_F(PasswordGenerationPopupControllerImplTest, GetOrCreateTheSame) {
@@ -144,4 +157,24 @@ TEST_F(PasswordGenerationPopupControllerImplTest,
   EXPECT_TRUE(controller2);
 }
 
+TEST_F(PasswordGenerationPopupControllerImplTest, DestroyInPasswordAccepted) {
+  autofill::password_generation::PasswordGenerationUIData ui_data(
+      gfx::RectF(100, 20), 20 /*max_length*/, base::ASCIIToUTF16("element"),
+      100 /*generation_element_id*/, base::i18n::TextDirection(),
+      autofill::PasswordForm());
+  auto driver = CreateDriver();
+  std::unique_ptr<content::WebContents> web_contents = CreateTestWebContents();
+  base::WeakPtr<PasswordGenerationPopupController> controller =
+      PasswordGenerationPopupControllerImpl::GetOrCreate(
+          nullptr /*previous*/, ui_data.bounds, ui_data, driver->AsWeakPtr(),
+          nullptr, web_contents.get(), main_rfh());
+
+  // Destroying the controller in GeneratedPasswordAccepted() should not cause a
+  // crash.
+  EXPECT_CALL(*driver,
+              GeneratedPasswordAccepted(_, 100 /*generation_element_id*/, _))
+      .WillOnce([controller](auto, auto, auto) { controller->Hide(); });
+  controller->PasswordAccepted();
+}
+
 }  // namespace

components/password_manager/content/browser/content_password_manager_driver.cc

@@ -124,6 +124,14 @@ void ContentPasswordManagerDriver::GeneratedPasswordAccepted(
   GetPasswordGenerationAgent()->GeneratedPasswordAccepted(password);
 }
 
+void ContentPasswordManagerDriver::GeneratedPasswordAccepted(
+    const autofill::FormData& form_data,
+    uint32_t generation_element_id,
+    const base::string16& password) {
+  GetPasswordManager()->OnGeneratedPasswordAccepted(
+      this, form_data, generation_element_id, password);
+}
+
 void ContentPasswordManagerDriver::FillSuggestion(
     const base::string16& username,
     const base::string16& password) {

components/password_manager/content/browser/content_password_manager_driver.h

@@ -62,6 +62,9 @@ class ContentPasswordManagerDriver
   void AutofillDataReceived(
       const autofill::FormsPredictionsMap& predictions) override;
   void GeneratedPasswordAccepted(const base::string16& password) override;
+  void GeneratedPasswordAccepted(const autofill::FormData& form_data,
+                                 uint32_t generation_element_id,
+                                 const base::string16& password) override;
   void FillSuggestion(const base::string16& username,
                       const base::string16& password) override;
   void FillIntoFocusedField(bool is_password,

components/password_manager/core/browser/password_manager_driver.h

@@ -55,8 +55,16 @@ class PasswordManagerDriver
       const autofill::FormsPredictionsMap& predictions) {}
 
   // Notifies the driver that the user has accepted a generated password.
+  // TODO(crbug/936011): delete this method. The UI should call the one below.
   virtual void GeneratedPasswordAccepted(const base::string16& password) = 0;
 
+  // Notifies the password manager that the user has accepted a generated
+  // password. The password manager can bring up some disambiguation UI in
+  // response.
+  virtual void GeneratedPasswordAccepted(const autofill::FormData& form_data,
+                                         uint32_t generation_element_id,
+                                         const base::string16& password) {}
+
   // Tells the driver to fill the form with the |username| and |password|.
   virtual void FillSuggestion(const base::string16& username,
                               const base::string16& password) = 0;