[ios] Added web// public API to let embedder observe loading progress.

ios/web/web_state/web_state_impl.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_WEB_WEB_STATE_WEB_STATE_IMPL_H_
 #define IOS_WEB_WEB_STATE_WEB_STATE_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 23 matching lines @@
 }
 
 namespace web {
 
 class BrowserState;
 struct Credential;
 struct FaviconURL;
 struct LoadCommittedDetails;
 class NavigationManager;
 class WebInterstitialImpl;
+class WebStateDelegate;
 class WebStateFacadeDelegate;
 class WebStatePolicyDecider;
 class WebUIIOS;
 
 // Implementation of WebState.
 // Generally mirrors //content's WebContents implementation.
 // General notes on expected WebStateImpl ownership patterns:
 //  - Outside of tests, WebStateImpls are created
 //      (a) By @Tab, when creating a new Tab.
 //      (b) By @SessionWindow, when decoding a saved session.
@@ skipping 155 matching lines @@
   RequestTrackerImpl* GetRequestTracker();
 
   // Lazily creates (if necessary) and returns |request_group_id_|.
   // IMPORTANT: This should not be used for anything other than associating this
   // instance to network requests.
   // This function is only intended to be used in web/.
   // TODO(stuartmorgan): Move this method in an implementation file in web/.
   NSString* GetRequestGroupID();
 
   // WebState:
+  WebStateDelegate* GetDelegate() override;
+  void SetDelegate(WebStateDelegate* delegate) override;
   UIView* GetView() override;
   BrowserState* GetBrowserState() const override;
   void OpenURL(const WebState::OpenURLParams& params) override;
   NavigationManager* GetNavigationManager() override;
   CRWJSInjectionReceiver* GetJSInjectionReceiver() const override;
   const std::string& GetContentLanguageHeader() const override;
   const std::string& GetContentsMimeType() const override;
   bool ContentIsHTML() const override;
   const base::string16& GetTitle() const override;
   bool IsLoading() const override;
@@ skipping 14 matching lines @@
                     bool bypass_cache,
                     const ImageDownloadCallback& callback) override;
   base::WeakPtr<WebState> AsWeakPtr() override;
 
   // Adds |interstitial|'s view to the web controller's content view.
   void ShowWebInterstitial(WebInterstitialImpl* interstitial);
 
   // Called to dismiss the currently-displayed transient content view.
   void ClearTransientContentView();
 
+  // Notifies the delegate that the load progress was updated.
+  void SendChangeLoadProgress(double progress);
+
   // NavigationManagerDelegate:
   void NavigateToPendingEntry() override;
   void LoadURLWithParams(const NavigationManager::WebLoadParams&) override;
   void OnNavigationItemsPruned(size_t pruned_item_count) override;
   void OnNavigationItemChanged() override;
   void OnNavigationItemCommitted(
       const LoadCommittedDetails& load_details) override;
   WebState* GetWebState() override;
 
  protected:
   void AddObserver(WebStateObserver* observer) override;
   void RemoveObserver(WebStateObserver* observer) override;
   void AddPolicyDecider(WebStatePolicyDecider* decider) override;
   void RemovePolicyDecider(WebStatePolicyDecider* decider) override;
 
  private:
+  // Unowned delegate.

[rohitrao (ping after 24h), 2016/04/13 12:01:13]

We generally use "weak" instead of "unowned".

[Eugene But (OOO till 7-30), 2016/04/13 15:03:53]

Agree that Bling generally use "weak". But "weak" means something specific in
Objective-C world, a reference which is either valid or null and never dangles.
Because of that I don't want to use the same name for different things.  Updated
the comment, since no one lines "Unowned" word: "Delegate, not owned by this
object."

+  WebStateDelegate* delegate_;
+
   // Creates a WebUIIOS object for |url| that is owned by the caller. Returns
   // nullptr if |url| does not correspond to a WebUI page.
   WebUIIOS* CreateWebUIIOS(const GURL& url);
 
   // Updates the HTTP response headers for the main page using the headers
   // passed to the OnHttpResponseHeadersReceived() function below.
   // GetHttpResponseHeaders() can be used to get the headers.
   void UpdateHttpResponseHeaders(const GURL& url);
 
   // Returns true if |web_controller_| has been set.
@@ skipping 57 matching lines @@
   // any WeakPtrs to WebStateImpl are invalidated before its member variable's
   // destructors are executed, rendering them invalid.
   base::WeakPtrFactory<WebState> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebStateImpl);
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_WEB_STATE_WEB_STATE_IMPL_H_