cbui: remove ExtensionInstallDialogView GetDialogButtonLabel

This dialog gets its strings from an ExtensionInstallPrompt::Prompt, via
the Get{Accept,Abort}ButtonLabel methods. Those methods, in turn, depend
on two fields of Prompt: type_ and extension_. Better yet, type_ is
already const.

I attempted to make extension_ const but wasn't able to do so.  Instead,
this change relies on the current behavior of that class, which is that
it is always used like this:

  auto prompt = make_unique<Prompt>();
  // somewhere else:
  prompt->set_extension(...);
  // yet a third place:
  ShowDialog(..., std::move(prompt), ...)

Not all the places where Prompt is constructed have ready access to the
extension it will eventually represent, which makes passing the
extension as a constructor parameter to Prompt infeasible. Rats.

This change calls the prompt from ExtensionInstallDialogView's
constructor to get the appropriate button labels and apply them.

Bug: 1011446
Change-Id: If4ceff51f3aa4a5ca3cb8c3013954748377c8544
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872420Reviewed-by: Robert Liao <robliao@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708189}

chrome/browser/ui/views/extensions/extension_install_dialog_view.cc

@@ -247,10 +247,16 @@ ExtensionInstallDialogView::ExtensionInstallDialogView(
       scroll_view_(nullptr),
       handled_result_(false),
       install_button_enabled_(false) {
+  DCHECK(prompt_->extension());
+
   DialogDelegate::set_default_button(ui::DIALOG_BUTTON_CANCEL);
   DialogDelegate::set_draggable(true);
   if (prompt_->has_webstore_data())
     DialogDelegate::SetExtraView(CreatePromptLink(this));
+  DialogDelegate::set_button_label(ui::DIALOG_BUTTON_OK,
+                                   prompt_->GetAcceptButtonLabel());
+  DialogDelegate::set_button_label(ui::DIALOG_BUTTON_CANCEL,
+                                   prompt_->GetAbortButtonLabel());
   set_close_on_deactivate(false);
   CreateContents();
 
@@ -404,19 +410,6 @@ int ExtensionInstallDialogView::GetDialogButtons() const {
   return buttons;
 }
 
-base::string16 ExtensionInstallDialogView::GetDialogButtonLabel(
-    ui::DialogButton button) const {
-  switch (button) {
-    case ui::DIALOG_BUTTON_OK:
-      return prompt_->GetAcceptButtonLabel();
-    case ui::DIALOG_BUTTON_CANCEL:
-      return prompt_->GetAbortButtonLabel();
-    default:
-      NOTREACHED();
-      return base::string16();
-  }
-}
-
 bool ExtensionInstallDialogView::IsDialogButtonEnabled(
     ui::DialogButton button) const {
   if (button == ui::DIALOG_BUTTON_OK)

chrome/browser/ui/views/extensions/extension_install_dialog_view.h

@@ -60,7 +60,6 @@ class ExtensionInstallDialogView : public views::BubbleDialogDelegateView,
   bool Cancel() override;
   bool Accept() override;
   int GetDialogButtons() const override;
-  base::string16 GetDialogButtonLabel(ui::DialogButton button) const override;
   bool IsDialogButtonEnabled(ui::DialogButton button) const override;
   bool ShouldShowCloseButton() const override;