[ios clean] Consumer interface for WebContents

ios/clean/chrome/browser/ui/web_contents/web_coordinator.mm

 // Copyright 2016 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.
 
 // ======                        New Architecture                         =====
 // =         This code is only used in the new iOS Chrome architecture.       =
 // ============================================================================
 
 #import "ios/clean/chrome/browser/ui/web_contents/web_coordinator.h"
 
 #import "ios/clean/chrome/browser/browser_coordinator+internal.h"
+#import "ios/clean/chrome/browser/ui/web_contents/web_contents_mediator.h"
 #import "ios/clean/chrome/browser/ui/web_contents/web_contents_view_controller.h"
 #import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 #include "ios/web/public/web_state/web_state.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 @interface WebCoordinator ()
-
 @property(nonatomic, strong) WebContentsViewController* viewController;
-
+@property(nonatomic, strong) WebContentsMediator* mediator;
 @end
 
 @implementation WebCoordinator
 @synthesize webState = _webState;
 @synthesize viewController = _viewController;
+@synthesize mediator = _mediator;
+
+- (instancetype)init {
+  if ((self = [super init])) {
+    _mediator = [[WebContentsMediator alloc] init];
+  }
+  return self;
+}
+
+- (void)setWebState:(web::WebState*)webState {
+  _webState = webState;

[edchin, 2017/02/02 22:17:53]

Consistent use of property accessor. 

[marq (ping after 24h), 2017/02/03 09:48:10]

Again, this is the setter method; I have to use the ivar directly.

[edchin, 2017/02/03 15:33:38]

You're right. I should have seen that this is the setter override.

+  self.mediator.webState = self.webState;
+}
 
 - (void)start {
-  self.webState->SetWebUsageEnabled(true);
-  self.viewController =
-      [[WebContentsViewController alloc] initWithWebState:self.webState];
+  self.viewController = [[WebContentsViewController alloc] init];
+  self.mediator.consumer = self.viewController;
 
   // Reminder: this is a no-op if |baseViewController| is nil, for example
   // when this coordinator's view controller will be contained instead of
   // presented.
   [self.context.baseViewController presentViewController:self.viewController
                                                 animated:self.context.animated
                                               completion:nil];
 }
 
 - (void)stop {
-  self.webState->SetWebUsageEnabled(false);
+  // PLACEHOLDER: This is how the webUsageEnabled is set to false. Find a
+  // better way in the future.

[edchin, 2017/02/02 22:17:53]

It is not clear to me why we should set webUsageEnabled to false. Can you
explain this comment?

[marq (ping after 24h), 2017/02/03 09:48:10]

webUsageEnabled means that the WebState is attached to a WKWebView instance. It
must be set to true before accessing the webState's view via GetView(), and
should be set to false when the web view isn't being displayed so  we can free
memory (among other things).

I'll expand the comment.

[edchin, 2017/02/03 15:33:38]

Acknowledged.

+  self.mediator.webState = nullptr;
 }
 
 @end