Refactor: Rename ShowManualPasswordGenerationPopup and expand comment

The documentation is expanded to reflect that this is the callback
executed at the end of the manual (user-triggered) generation flow. The
method is renamed to ManualGenerationResultAvailable to match its
counterpart AutomaticGenerationAvailable and avoid confusion with
ShowPasswordGenerationPopup. The renaming is also justified by the fact
that on some platforms a dialog gets shown instead of popup.

Bug: 1060131
Change-Id: I147daae8fe3cb4b87be576c9841f87475ae3c63b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2144154Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Victor Vianna <victorvianna@google.com>
Cr-Commit-Position: refs/heads/master@{#757845}

chrome/browser/password_manager/chrome_password_manager_client.cc

@@ -470,7 +470,7 @@ void ChromePasswordManagerClient::GeneratePassword() {
   // Using unretained pointer is safe because |this| outlives
   // ContentPasswordManagerDriver that holds the connection.
   content_driver->GeneratePassword(base::BindOnce(
-      &ChromePasswordManagerClient::ShowManualPasswordGenerationPopup,
+      &ChromePasswordManagerClient::ManualGenerationResultAvailable,
       base::Unretained(this), base::AsWeakPtr(content_driver)));
 }
 
@@ -1264,7 +1264,7 @@ bool ChromePasswordManagerClient::CanShowBubbleOnURL(const GURL& url) {
           scheme != content::kChromeDevToolsScheme);
 }
 
-void ChromePasswordManagerClient::ShowManualPasswordGenerationPopup(
+void ChromePasswordManagerClient::ManualGenerationResultAvailable(
     base::WeakPtr<password_manager::ContentPasswordManagerDriver> driver,
     const base::Optional<
         autofill::password_generation::PasswordGenerationUIData>& ui_data) {

chrome/browser/password_manager/chrome_password_manager_client.h

@@ -300,9 +300,10 @@ class ChromePasswordManagerClient
   // without custom sync passphrase.
   static bool ShouldAnnotateNavigationEntries(Profile* profile);
 
-  // |ui_data| is empty in case the renderer failed to start manual generation.
-  // In this case nothing should happen.
-  void ShowManualPasswordGenerationPopup(
+  // Called back by the PasswordGenerationAgent when the manual generation flow
+  // is completed. If |ui_data| is non-empty, will create a UI to display the
+  // generated password. Otherwise, nothing will happen.
+  void ManualGenerationResultAvailable(
       base::WeakPtr<password_manager::ContentPasswordManagerDriver> driver,
       const base::Optional<
           autofill::password_generation::PasswordGenerationUIData>& ui_data);