[Cleanup] rename WebContentsModalDialogManager::IsShowingDialog() to IsDialogActive()

The function tests whether web contents modal dialogs are active, rather
than if they are actually showing. This updates the name accordingly
and resolves the TODO.

BUG=157161

Review URL: https://chromiumcodereview.appspot.com/23815006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222289 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/repost_form_warning_browsertest.cc b/chrome/browser/repost_form_warning_browsertest.cc
index 6dc64b3..ff0be0d1 100644
--- a/chrome/browser/repost_form_warning_browsertest.cc
+++ b/chrome/browser/repost_form_warning_browsertest.cc
@@ -42,13 +42,13 @@
   // There should only be one dialog open.
   WebContentsModalDialogManager* web_contents_modal_dialog_manager =
       WebContentsModalDialogManager::FromWebContents(web_contents);
-  EXPECT_TRUE(web_contents_modal_dialog_manager->IsShowingDialog());
+  EXPECT_TRUE(web_contents_modal_dialog_manager->IsDialogActive());
 
   // Navigate away from the page (this is when the test usually crashes).
   ui_test_utils::NavigateToURL(browser(), test_server()->GetURL("bar"));
 
   // The dialog should've been closed.
-  EXPECT_FALSE(web_contents_modal_dialog_manager->IsShowingDialog());
+  EXPECT_FALSE(web_contents_modal_dialog_manager->IsDialogActive());
 }
 
 // If becomes flaky, disable on Windows and use http://crbug.com/47228