Re-land alexbost's experimental offscreenTabs API.

chrome/browser/extensions/extension_tab_util.cc

Index: chrome/browser/extensions/extension_tab_util.cc
diff --git a/chrome/browser/extensions/extension_tab_util.cc b/chrome/browser/extensions/extension_tab_util.cc
index 98bd0983b49ef860892bc7b69687b50085de147a..9f91a3a20add71599a40da204cd38db04550fdaa 100644
--- a/chrome/browser/extensions/extension_tab_util.cc
+++ b/chrome/browser/extensions/extension_tab_util.cc
@@ -12,9 +12,13 @@
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/sessions/restore_tab_helper.h"
 #include "chrome/browser/extensions/extension_tabs_module_constants.h"
+#include "chrome/browser/net/url_fixer_upper.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/url_constants.h"
 #include "content/public/browser/favicon_status.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/web_contents.h"
+#include "googleurl/src/gurl.h"
 
 namespace keys = extension_tabs_module_constants;
 namespace errors = extension_manifest_errors;
@@ -223,3 +227,21 @@ bool ExtensionTabUtil::GetTabById(int tab_id,
   }
   return false;
 }
+
+GURL ExtensionTabUtil::ResolvePossiblyRelativeURL(const std::string& url_string,
+                                                  const Extension* extension) {
+  GURL url = GURL(url_string);
+  if (!url.is_valid())
+    url = extension->GetResourceURL(url_string);
+
+  return url;
+}
+
+bool ExtensionTabUtil::IsCrashURL(const GURL& url) {
+  // Check a fixed-up URL, to normalize the scheme and parse hosts correctly.
+  GURL fixed_url =
+      URLFixerUpper::FixupURL(url.possibly_invalid_spec(), std::string());
+  return (fixed_url.SchemeIs(chrome::kChromeUIScheme) &&
+          (fixed_url.host() == chrome::kChromeUIBrowserCrashHost ||
+           fixed_url.host() == chrome::kChromeUICrashHost));
+}