[ios] Add AttachBrowserAgents method to ChromeBrowserProvider

This method will allow for the creation of embedder-specific methods that are
tied to a specific Browser.

Bug: 790886
Change-Id: I4fdf5b33c45910fe96eff834fc66843328ca05ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1838263Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728532}

ios/chrome/browser/main/BUILD.gn

@@ -40,6 +40,7 @@ source_set("main") {
     "//ios/chrome/browser/ui/commands",
     "//ios/chrome/browser/ui/infobars:feature_flags",
     "//ios/chrome/browser/web_state_list",
+    "//ios/public/provider/chrome/browser",
   ]
   configs += [ "//build/config/compiler:enable_arc" ]
 }

ios/chrome/browser/main/browser_agent_util.mm

@@ -10,6 +10,7 @@
 #import "ios/chrome/browser/infobars/infobar_badge_browser_agent.h"
 #import "ios/chrome/browser/ui/infobars/infobar_feature.h"
 #import "ios/chrome/browser/web_state_list/tab_insertion_browser_agent.h"
+#include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -24,4 +25,7 @@ void AttachBrowserAgents(Browser* browser) {
   if (base::FeatureList::IsEnabled(kInfobarOverlayUI)) {
     InfobarBadgeBrowserAgent::CreateForBrowser(browser);
   }
+  // This needs to be called last in case any downstream browser agents need to
+  // access upstream agents created earlier in this function.
+  ios::GetChromeBrowserProvider()->AttachBrowserAgents(browser);
 }

ios/public/provider/chrome/browser/chrome_browser_provider.h

@@ -40,6 +40,7 @@ class GURL;
 @protocol LogoVendor;
 @class UITextField;
 @class UIView;
+class Browser;
 
 namespace ios {
 
@@ -120,6 +121,9 @@ class ChromeBrowserProvider {
   // Attaches any embedder-specific tab helpers to the given |web_state|.
   virtual void AttachTabHelpers(web::WebState* web_state) const;
 
+  // Attaches any embedder-specific browser agents to the given |browser|.
+  virtual void AttachBrowserAgents(Browser* browser) const;
+
   // Returns an instance of the voice search provider, if one exists.
   virtual VoiceSearchProvider* GetVoiceSearchProvider() const;
 

ios/public/provider/chrome/browser/chrome_browser_provider.mm

@@ -84,6 +84,8 @@ UITextField* ChromeBrowserProvider::CreateStyledTextField() const {
 
 void ChromeBrowserProvider::AttachTabHelpers(web::WebState* web_state) const {}
 
+void ChromeBrowserProvider::AttachBrowserAgents(Browser* browser) const {}
+
 VoiceSearchProvider* ChromeBrowserProvider::GetVoiceSearchProvider() const {
   return nullptr;
 }