[ios] Adds support for Find in Page to the new architecture.

ios/clean/chrome/browser/ui/find_in_page/find_in_page_mediator.h

Index: ios/clean/chrome/browser/ui/find_in_page/find_in_page_mediator.h
diff --git a/ios/clean/chrome/browser/ui/find_in_page/find_in_page_mediator.h b/ios/clean/chrome/browser/ui/find_in_page/find_in_page_mediator.h
new file mode 100644
index 0000000000000000000000000000000000000000..45124103bae4e40670d37259d65c0d74fe07dc1f
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+++ b/ios/clean/chrome/browser/ui/find_in_page/find_in_page_mediator.h
@@ -0,0 +1,39 @@
+// 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.
+
+#ifndef IOS_CLEAN_CHROME_BROWSER_UI_FIND_IN_PAGE_FIND_IN_PAGE_MEDIATOR_H_
+#define IOS_CLEAN_CHROME_BROWSER_UI_FIND_IN_PAGE_FIND_IN_PAGE_MEDIATOR_H_
+
+#import <Foundation/Foundation.h>
+
+@protocol FindInPageConsumer;
+@protocol FindInPageVisibilityCommands;
+class WebStateList;
+
+// FindInPageConsumerProvider allows FindInPageMediator to ask its provider to
+// return a |consumer| object.
+@protocol FindInPageConsumerProvider
+// Returns the consumer that should be updated by the caller.  The returned
+// |consumer| can be nil, in which case no updates are necessary.
+@property(nonatomic, readonly, weak) id<FindInPageConsumer> consumer;
+@end
+
+// FindInPageMediator provides updates to a FindInPageConsumer based on observer
+// callbacks from multiple models.
+@interface FindInPageMediator : NSObject
+
+- (instancetype)initWithWebStateList:(WebStateList*)webStateList
+                            provider:(id<FindInPageConsumerProvider>)provider
+                          dispatcher:
+                              (id<FindInPageVisibilityCommands>)dispatcher
+    NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+// Stops finding in page for the current active WebState.
+- (void)stopFinding;
+
+@end
+
+#endif  // IOS_CLEAN_CHROME_BROWSER_UI_FIND_IN_PAGE_FIND_IN_PAGE_MEDIATOR_H_