Created web::UserAgentType.

ios/web/navigation/navigation_item_impl.mm

Index: ios/web/navigation/navigation_item_impl.mm
diff --git a/ios/web/navigation/navigation_item_impl.mm b/ios/web/navigation/navigation_item_impl.mm
index 31f357566080a0b3b5613312130691500edc34bc..bf3cec8042730de964fbcccac59194927c5001b6 100644
--- a/ios/web/navigation/navigation_item_impl.mm
+++ b/ios/web/navigation/navigation_item_impl.mm
@@ -12,6 +12,7 @@
 #include "base/logging.h"
 #include "components/url_formatter/url_formatter.h"
 #import "ios/web/navigation/navigation_manager_impl.h"
+#import "ios/web/public/web_client.h"
 #include "ui/base/page_transition_types.h"
 #include "ui/gfx/text_elider.h"
 
@@ -40,7 +41,7 @@ static int GetUniqueIDInConstructor() {
 NavigationItemImpl::NavigationItemImpl()
     : unique_id_(GetUniqueIDInConstructor()),
       transition_type_(ui::PAGE_TRANSITION_LINK),
-      is_overriding_user_agent_(false),
+      user_agent_type_(UserAgentType::MOBILE),
       is_created_from_push_state_(false),
       has_state_been_replaced_(false),
       is_created_from_hash_change_(false),
@@ -64,7 +65,7 @@ static int GetUniqueIDInConstructor() {
       favicon_(item.favicon_),
       ssl_(item.ssl_),
       timestamp_(item.timestamp_),
-      is_overriding_user_agent_(item.is_overriding_user_agent_),
+      user_agent_type_(item.user_agent_type_),
       http_request_headers_([item.http_request_headers_ copy]),
       serialized_state_object_([item.serialized_state_object_ copy]),
       is_created_from_push_state_(item.is_created_from_push_state_),
@@ -206,13 +207,16 @@ static int GetUniqueIDInConstructor() {
   return timestamp_;
 }
 
-void NavigationItemImpl::SetIsOverridingUserAgent(
-    bool is_overriding_user_agent) {
-  is_overriding_user_agent_ = is_overriding_user_agent;
+void NavigationItemImpl::SetUserAgentType(UserAgentType type) {
+  user_agent_type_ = type;
+  url_ = original_request_url_;

[Eugene But (OOO till 7-30), 2017/02/27 23:55:18]

Why? The old code and NavigationEntryImpl is not doing this. on iOS we should
aim for having similar interface to content.

[liaoyuke, 2017/03/01 01:33:56]

Actually, now I think this is bad. We may justify that it's OK to add side
effects to the setUserAgentType function in tools_menu_view_controller, but
definitely not here, if you take a look at other getters and setters in this
file, they are pretty clean, and only does one thing that the function name
implies.

By the way, even if we are doing this, shouldn't url_ be set as the original url
of last user item instead of the original url of visible item?

[kkhorimoto, 2017/03/01 18:29:25]

I've reverted this change, instead only setting |user_agent_type_| and doing the
DCHECK below.  The motivation for adding this was to ensure that changing the UA
type would erase details of redirection due to UA sniffing (i.e. www.page.com =>
m.page.com), and would force users of this NavigationItem to request the correct
URL when retrying the load.  When the UA reload code is rewritten by Yuke, we'll
need to ensure that |original_request_url_| is called for the load instead of
the virtual URL.

+  virtual_url_ = GURL();
+  DCHECK_EQ(GetWebClient()->IsAppSpecificURL(GetVirtualURL()),
+            user_agent_type_ == UserAgentType::NONE);
 }
 
-bool NavigationItemImpl::IsOverridingUserAgent() const {
-  return is_overriding_user_agent_;
+UserAgentType NavigationItemImpl::GetUserAgentType() const {
+  return user_agent_type_;
 }
 
 bool NavigationItemImpl::HasPostData() const {