Remove iOS ifdefs in src/content.

content/public/browser/navigation_controller.h

Index: content/public/browser/navigation_controller.h
diff --git a/content/public/browser/navigation_controller.h b/content/public/browser/navigation_controller.h
index 76d6de2a0a41291667cb5508a90d495c7e42751f..a540ee0e1b8c5b1b454dec85de4f6ff99b840809 100644
--- a/content/public/browser/navigation_controller.h
+++ b/content/public/browser/navigation_controller.h
@@ -395,9 +395,7 @@ class NavigationController {
 
   // Random --------------------------------------------------------------------
 
-  // Session storage depends on dom_storage that depends on blink::WebString,
-  // which cannot be used on iOS.
-#if !defined(OS_IOS)
+  // Session storage depends on dom_storage that depends on blink::WebString.
   // Returns all the SessionStorageNamespace objects that this
   // NavigationController knows about, the map key is a StoragePartition id.
   virtual const SessionStorageNamespaceMap&
@@ -406,7 +404,6 @@ class NavigationController {
   // TODO(ajwong): Remove this once prerendering, instant, and session restore
   // are migrated.
   virtual SessionStorageNamespace* GetDefaultSessionStorageNamespace() = 0;
-#endif
 
   // Sets the max restored page ID this NavigationController has seen, if it
   // was restored from a previous session.