[ios] Take snapshot for tab grid.

ios/clean/chrome/browser/ui/tab_collection/tab_collection_mediator.mm

 // Copyright 2017 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/clean/chrome/browser/ui/tab_collection/tab_collection_mediator.h"
 
+#include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/scoped_observer.h"
 #include "base/strings/sys_string_conversions.h"
+#import "ios/chrome/browser/snapshots/snapshot_cache.h"
+#import "ios/chrome/browser/snapshots/snapshot_constants.h"
 #import "ios/chrome/browser/web/tab_id_tab_helper.h"
 #import "ios/chrome/browser/web_state_list/web_state_list.h"
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_consumer.h"
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_item.h"
 #include "ios/web/public/web_state/web_state.h"
 #import "ios/web/public/web_state/web_state_observer_bridge.h"
+#include "ui/gfx/image/image.h"

[danakj, 2017/07/11 19:14:15]

I thought IOS cant depend on skia?

 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 @interface TabCollectionMediator ()<CRWWebStateObserver>
 @end
 
 @implementation TabCollectionMediator {
   std::unique_ptr<WebStateListObserverBridge> _webStateListObserver;
@@ skipping 15 matching lines @@
   }
   return self;
 }
 
 - (void)dealloc {
   [self disconnect];
 }
 
 #pragma mark - Public
 
+- (void)takeSnapshotWithCache:(SnapshotCache*)snapshotCache {
+  web::WebState* webState = self.webStateList->GetActiveWebState();
+  TabIdTabHelper* tabHelper = TabIdTabHelper::FromWebState(webState);
+  DCHECK(tabHelper);
+  NSString* tabID = tabHelper->tab_id();
+  int index = self.webStateList->active_index();
+  __weak TabCollectionMediator* weakSelf = self;
+  webState->TakeSnapshot(base::BindBlockArc(^(const gfx::Image& snapshot) {
+                           [snapshotCache setImage:snapshot.ToUIImage()
+                                     withSessionID:tabID];
+                           [weakSelf.consumer updateSnapshotAtIndex:index];
+                         }),
+                         kSnapshotThumbnailSize);
+}
+
 - (void)disconnect {
   _webStateList = nullptr;
   _webStateObserver.reset();
   _scopedWebStateListObserver->RemoveAll();
 }
 
 #pragma mark - Properties
 
 - (void)setWebStateList:(WebStateList*)webStateList {
   DCHECK(webStateList);
@@ skipping 104 matching lines @@
 - (void)populateConsumerItems {
   if (self.consumer && self.webStateList) {
     [self.consumer
         populateItems:[self
                           tabCollectionItemsFromWebStateList:self.webStateList]
         selectedIndex:self.webStateList->active_index()];
   }
 }
 
 @end