Fixed more Document leaks in Autofill

Some Autofill-related code can hold persistent reference to last
changed or focused <input> element that cause leak of whole Documents
containing such element after navigation to other page.

Some leaks fixed in https://chromium-review.googlesource.com/939224
This CL fixes other related leaks.

Bug: 734427
Change-Id: Ic084d0670cccb9d11595d0bde8cf0d605bfa8911
Reviewed-on: https://chromium-review.googlesource.com/970582Reviewed-by: Evan Stade <estade@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Commit-Queue: Vadym Doroshenko <dvadym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544404}

components/autofill/content/renderer/autofill_agent.cc

@@ -968,6 +968,7 @@ bool AutofillAgent::GetSubmittedForm(FormData* form) {
 
 void AutofillAgent::ResetLastInteractedElements() {
   last_interacted_form_.Reset();
+  last_clicked_form_control_element_for_testing_.Reset();
   formless_elements_user_edited_.clear();
   provisionally_saved_form_.reset();
 }

components/autofill/content/renderer/form_tracker.cc

@@ -143,8 +143,10 @@ void FormTracker::FormControlDidChangeImpl(
 void FormTracker::DidCommitProvisionalLoad(bool is_new_navigation,
                                            bool is_same_document_navigation) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(form_tracker_sequence_checker_);
-  if (!is_same_document_navigation)
+  if (!is_same_document_navigation) {
+    ResetLastInteractedElements();
     return;
+  }
 
   FireSubmissionIfFormDisappear(SubmissionSource::SAME_DOCUMENT_NAVIGATION);
 }

components/autofill/content/renderer/password_generation_agent.cc

@@ -178,6 +178,14 @@ void PasswordGenerationAgent::BindRequest(
   binding_.Bind(std::move(request));
 }
 
+void PasswordGenerationAgent::DidCommitProvisionalLoad(
+    bool /*is_new_navigation*/, bool is_same_document_navigation) {
+  if (is_same_document_navigation)
+    return;
+  generation_element_.Reset();
+  last_focused_password_element_.Reset();
+}
+
 void PasswordGenerationAgent::DidFinishDocumentLoad() {
   // Update stats for main frame navigation.
   if (!render_frame()->GetWebFrame()->Parent()) {

components/autofill/content/renderer/password_generation_agent.h

@@ -94,6 +94,8 @@ class PasswordGenerationAgent : public content::RenderFrameObserver,
   typedef std::vector<AccountCreationFormData> AccountCreationFormDataList;
 
   // RenderFrameObserver:
+  void DidCommitProvisionalLoad(bool is_new_navigation,
+                                bool is_same_document_navigation) override;
   void DidFinishDocumentLoad() override;
   void DidFinishLoad() override;
   void OnDestruct() override;