Adds methods for Cast support to ios::ChromeBrowserProvider.

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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IOS_PUBLIC_PROVIDER_CHROME_BROWSER_CHROME_BROWSER_PROVIDER_H_
 #define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_CHROME_BROWSER_PROVIDER_H_
 
 #include <CoreGraphics/CoreGraphics.h>
 #import <Foundation/Foundation.h>
 #include <stddef.h>
@@ skipping 14 matching lines @@
 
 namespace autofill {
 class CardUnmaskPromptController;
 class CardUnmaskPromptView;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
+namespace web {
+class WebState;
+}
+
 namespace sync_sessions {
 class SyncedWindowDelegatesGetter;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 @protocol InfoBarViewProtocol;
 @protocol TextFieldStyling;
@@ skipping 63 matching lines @@
   // Note. |callback| is always run asynchronously.
   virtual void GetFaviconForURL(
       ChromeBrowserState* browser_state,
       const GURL& page_url,
       const std::vector<int>& desired_sizes_in_pixel,
       const favicon_base::FaviconResultsCallback& callback) const;
   // Creates and returns a new styled text field with the given |frame|.
   virtual UITextField<TextFieldStyling>* CreateStyledTextField(
       CGRect frame) const NS_RETURNS_RETAINED;
 
+  // Initializes the cast service.  Should be called soon after the given
+  // |tab_model| is created.
+  // TODO(rohitrao): Change from |id| to |TabModel*| once TabModel is moved into

[rohitrao (ping after 24h), 2016/10/05 20:19:56]

Thoughts on using id here instead of TabModel*?  Are there any better options?

+  // the Chromium tree.
+  virtual void InitializeCastService(id tab_model) const;
+
+  // Adds Cast Sender API support to the given |web_state|, if it is supported
+  // by this embedder.
+  virtual void AddCastAPISupportToWebState(web::WebState* web_state,
+                                           NSString* tab_id) const;

[rohitrao (ping after 24h), 2016/10/05 20:19:56]

I thought about having this API take a std::string instead, but that would
require conversions from and to NSString.  It's only once per tab though, so we
could take the hit if the API would be better with std::string.

+
   // Returns whether safe browsing is enabled. See the comment on
   // metrics_services_manager_client.h for details on |on_update_callback|.
   virtual bool IsSafeBrowsingEnabled(const base::Closure& on_update_callback);
 
   // Returns the SyncedWindowDelegatesGetter implementation.
   virtual std::unique_ptr<sync_sessions::SyncedWindowDelegatesGetter>
   CreateSyncedWindowDelegatesGetter(ios::ChromeBrowserState* browser_state);
 };
 
 }  // namespace ios
 
 #endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_CHROME_BROWSER_PROVIDER_H_