MacViewsBrowser: Provide a stub for ChromeExtensionChooserDialog::ShowDialog()

Fixes a MacViewsBrowser link error after r397320, starting at
http://go/macviewsbuilder/builds/11045, like

Undefined symbols for architecture x86_64:
  "ChromeExtensionChooserDialog::ShowDialog(ChooserController*) const", referenced from:
      ChromeExtensionBluetoothChooser::ChromeExtensionBluetoothChooser

MacViewsBrowser needs a ShowDialog() symbol, which will provide the
toolkit-views implementation when it's ready.

BUG=425229, 613638
TBR=juncai@chromium.org

Review-Url: https://codereview.chromium.org/2036033003
Cr-Commit-Position: refs/heads/master@{#397911}

chrome/browser/extensions/chrome_extension_chooser_dialog.h

@@ -22,11 +22,7 @@ class ChromeExtensionChooserDialog {
 
   content::WebContents* web_contents() const { return web_contents_; }
 
-// TODO(juncai): remove this preprocessor directive once the non-Mac
-// implementation is done.
-#if defined(OS_MACOSX)
   void ShowDialog(ChooserController* chooser_controller) const;
-#endif  // defined(OS_MACOSX)
 
  private:
   content::WebContents* web_contents_;

chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc

@@ -15,9 +15,7 @@ ChromeExtensionBluetoothChooser::ChromeExtensionBluetoothChooser(
       new BluetoothChooserController(frame, event_handler));
   chooser_dialog_.reset(new ChromeExtensionChooserDialog(
       content::WebContents::FromRenderFrameHost(frame)));
-#if defined(OS_MACOSX)
   chooser_dialog_->ShowDialog(bluetooth_chooser_controller_.get());
-#endif  // defined(OS_MACOSX)
 }
 
 ChromeExtensionBluetoothChooser::~ChromeExtensionBluetoothChooser() {}

chrome/browser/ui/views/browser_dialogs_views.cc

@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/browser_dialogs.h"
 
 #include "chrome/browser/extensions/api/chrome_device_permissions_prompt.h"
+#include "chrome/browser/extensions/chrome_extension_chooser_dialog.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/ui/login/login_handler.h"
 #include "chrome/browser/ui/views/new_task_manager_view.h"
@@ -41,6 +42,12 @@ void ChromeDevicePermissionsPrompt::ShowDialog() {
   ShowDialogViews();
 }
 
+// TODO(juncai): Move this to the toolkit-views implementation file of this
+// dialog when it is implemented.
+void ChromeExtensionChooserDialog::ShowDialog(
+    ChooserController* chooser_controller) const {
+}
+
 namespace chrome {
 
 ui::TableModel* ShowTaskManager(Browser* browser) {