Implemented new Translate API for purely Objective-C clients.

ios/web_view/internal/cwv_web_view.mm

 // Copyright 2014 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.
 
 #import "ios/web_view/public/cwv_web_view.h"
 
 #include <memory>
 #include <utility>
 
 #import "base/ios/weak_nsobject.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "google_apis/google_api_keys.h"
 #import "ios/web/public/navigation_manager.h"
 #include "ios/web/public/referrer.h"
 #include "ios/web/public/reload_type.h"
 #import "ios/web/public/web_state/context_menu_params.h"
 #import "ios/web/public/web_state/js/crw_js_injection_receiver.h"
 #import "ios/web/public/web_state/ui/crw_web_delegate.h"
 #import "ios/web/public/web_state/web_state.h"
 #import "ios/web/public/web_state/web_state_delegate_bridge.h"
 #import "ios/web/public/web_state/web_state_observer_bridge.h"
 #import "ios/web_view/internal/cwv_html_element_internal.h"
 #import "ios/web_view/internal/cwv_navigation_action_internal.h"
 #import "ios/web_view/internal/cwv_web_view_configuration_internal.h"
+#import "ios/web_view/internal/translate/cwv_translation_controller_internal.h"
 #import "ios/web_view/internal/translate/web_view_translate_client.h"
 #include "ios/web_view/internal/web_view_browser_state.h"
 #import "ios/web_view/internal/web_view_java_script_dialog_presenter.h"
 #import "ios/web_view/internal/web_view_web_state_policy_decider.h"
 #import "ios/web_view/public/cwv_navigation_delegate.h"
 #import "ios/web_view/public/cwv_ui_delegate.h"
 #import "ios/web_view/public/cwv_web_view_configuration.h"
 #import "net/base/mac/url_conversions.h"
 #include "ui/base/page_transition_types.h"
 #include "url/gurl.h"
@@ skipping 39 matching lines @@
 @property(nonatomic, readwrite) double estimatedProgress;
 
 @end
 
 static NSString* gUserAgentProduct = nil;
 
 @implementation CWVWebView
 
 @synthesize configuration = _configuration;
 @synthesize navigationDelegate = _navigationDelegate;
-@synthesize translationDelegate = _translationDelegate;
 @synthesize estimatedProgress = _estimatedProgress;
 @synthesize UIDelegate = _UIDelegate;
+@synthesize translationController = _translationController;
 
 + (NSString*)userAgentProduct {
   return gUserAgentProduct;
 }
 
 + (void)setUserAgentProduct:(NSString*)product {
   gUserAgentProduct = [product copy];
 }
 
 + (void)setGoogleAPIKey:(NSString*)googleAPIKey
@@ skipping 82 matching lines @@
   [_webState->GetJSInjectionReceiver() executeJavaScript:javaScriptString
                                        completionHandler:completionHandler];
 }
 
 - (void)setUIDelegate:(id<CWVUIDelegate>)UIDelegate {
   _UIDelegate = UIDelegate;
 
   _javaScriptDialogPresenter->SetUIDelegate(_UIDelegate);
 }
 
-- (void)setTranslationDelegate:(id<CWVTranslateDelegate>)translationDelegate {
-  _translationDelegate = translationDelegate;
-  ios_web_view::WebViewTranslateClient::FromWebState(_webState.get())
-      ->set_translate_delegate(translationDelegate);
-}
-
 // -----------------------------------------------------------------------
 // WebStateObserver implementation.
 
 - (void)webState:(web::WebState*)webState
     didStartProvisionalNavigationForURL:(const GURL&)URL {
   SEL selector = @selector(webViewDidStartProvisionalNavigation:);
   if ([_navigationDelegate respondsToSelector:selector]) {
     [_navigationDelegate webViewDidStartProvisionalNavigation:self];
   }
 }
@@ skipping 77 matching lines @@
   if ([_UIDelegate respondsToSelector:selector]) {
     [_UIDelegate webViewDidClose:self];
   }
 }
 
 - (web::JavaScriptDialogPresenter*)javaScriptDialogPresenterForWebState:
     (web::WebState*)webState {
   return _javaScriptDialogPresenter.get();
 }
 
+#pragma mark - Translation
+
+- (CWVTranslationController*)translationController {

[Hiroshi Ichikawa, 2017/04/26 08:40:57]

When -resetWebStateWithSessionStorage: is called after the first call to
-translationController, I believe you need to update _translationController with
the new _webState.

FYI You may do something similar to my CL:
https://codereview.chromium.org/2842953002/

[jzw1, 2017/04/27 04:54:01]

Are you OK if i just nil it out _translationController inside resetWebState?

[Hiroshi Ichikawa, 2017/04/27 05:35:42]

I believe it doesn't work. Two cases:

1. The user stores |translationController| to a variable before -resetWebState
is called. Then the controller keeps referring to the old WebState.

2. The user assigns a delegate to |translationController| before -resetWebState
is called. Then the delegate won't be called after -resetWebState because the
delegate is not inherited to the new |translationController|.

One solution I can think of is to allow reassigning
CWVTranslationController.translateClient and reassign it in -resetWebState as I
do in:
https://codereview.chromium.org/2842953002/

[jzw1, 2017/04/27 07:03:18]

What if I just set a webState on translationController?

[Hiroshi Ichikawa, 2017/04/27 07:17:22]

Yeah it looks calling -[CWVTranslationController setWebState:] on -resetWebState
should work. Looks like -setWebState: already does the required job.

+  if (!_translationController) {
+    // Initialize Translate.
+    ios_web_view::WebViewTranslateClient::CreateForWebState(_webState.get());
+    ios_web_view::WebViewTranslateClient* translateClient =
+        ios_web_view::WebViewTranslateClient::FromWebState(_webState.get());
+    _translationController = [[CWVTranslationController alloc]
+        initWithWebViewTranslateClient:translateClient];
+  }
+  return _translationController;
+}
+
 #pragma mark - Preserving and Restoring State
 
 - (void)encodeRestorableStateWithCoder:(NSCoder*)coder {
   [super encodeRestorableStateWithCoder:coder];
   [coder encodeObject:_webState->BuildSessionStorage()
                forKey:kSessionStorageKey];
 }
 
 - (void)decodeRestorableStateWithCoder:(NSCoder*)coder {
   [super decodeRestorableStateWithCoder:coder];
@@ skipping 31 matching lines @@
   _webState->SetDelegate(_webStateDelegate.get());
 
   _webStatePolicyDecider =
       base::MakeUnique<ios_web_view::WebViewWebStatePolicyDecider>(
           _webState.get(), self);
 
   _javaScriptDialogPresenter =
       base::MakeUnique<ios_web_view::WebViewJavaScriptDialogPresenter>(self,
                                                                        nullptr);
 
-  // Initialize Translate.
-  ios_web_view::WebViewTranslateClient::CreateForWebState(_webState.get());
-
   [self addInternalWebViewAsSubview];
 }
 
 // Adds the web view provided by |_webState| as a subview unless it has already.
 - (void)addInternalWebViewAsSubview {
   UIView* subview = _webState->GetView();
   if (subview.superview == self) {
     return;
   }
   subview.frame = self.bounds;
   subview.autoresizingMask =
       UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
   [self addSubview:subview];
 }
 
 @end