[ios] Moved WebUI provider code to ios/web.

ios/chrome/browser/ui/webui/history/metrics_handler.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_WEBUI_HISTORY_METRICS_HANDLER_H_
 #define IOS_CHROME_BROWSER_UI_WEBUI_HISTORY_METRICS_HANDLER_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "ios/public/provider/web/web_ui_ios_message_handler.h"
+#include "ios/web/public/webui/web_ui_ios_message_handler.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // MetricsHandler
 
 // Let the page contents record UMA actions. Only use when you can't do it from
 // C++. For example, we currently use it to let the NTP log the position of the
 // Most Visited or Bookmark the user clicked on, as we don't get that
 // information through RequestOpenURL. You will need to update the metrics
 // dashboard with the action names you use, as our processor won't catch that
 // information (treat it as RecordComputedMetrics)
@@ skipping 21 matching lines @@
   // and the maximum allowed value, which can be at most 4000. The histogram
   // will use at most 100 buckets, one for each 1, 10, or 100 different values,
   // depending on the maximum value.
   void HandleRecordInHistogram(const base::ListValue* args);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MetricsHandler);
 };
 
 #endif  // IOS_CHROME_BROWSER_UI_WEBUI_HISTORY_METRICS_HANDLER_H_