[Suggestions] Rename ThumbnailManager to ImageManagerImpl

components/suggestions/proto/suggestions.proto

 // 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.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package suggestions;
 
@@ skipping 34 matching lines @@
 }
 
 // A list of URLs that should be filtered from the SuggestionsProfile.
 //
 // Next tag: 2
 message SuggestionsBlacklist {
   // URLs that make up the blacklist.
   repeated string urls = 1;
 }
 
-// ThumbnailData contains the data to represent a website thumbnail.
+// ImageData contains the data to represent a website image (e.g. thumbnail).
 //
 // Next tag: 3
-message ThumbnailData {
-  // The URL of the website represented by this Thumbnail.
+message ImageData {
+  // The URL of the website represented by this image.
   optional string url = 1;
 
   // Bitmap bytes, encoded as JPEG.
   optional bytes data = 2;
 }