[Suggestions] Create ImageEncoder, to abstract away image encode/decode.

components/suggestions.gypi

 # 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.
 
 {
   'targets': [
     {
       # GN version: //components/suggestions
       'target_name': 'suggestions',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../net/net.gyp:net',
         '../ui/gfx/gfx.gyp:gfx',
         '../url/url.gyp:url_lib',
         'components.gyp:keyed_service_core',
         'components.gyp:pref_registry',
         'components.gyp:variations',
         'components.gyp:variations_http_provider',
       ],
       'sources': [
         'suggestions/blacklist_store.cc',
         'suggestions/blacklist_store.h',
+        'suggestions/image_encoder.h',
         'suggestions/image_fetcher.h',
         'suggestions/image_fetcher_delegate.h',
         'suggestions/image_manager.cc',
         'suggestions/image_manager.h',
         'suggestions/proto/suggestions.proto',
         'suggestions/suggestions_pref_names.cc',
         'suggestions/suggestions_pref_names.h',
         'suggestions/suggestions_service.cc',
         'suggestions/suggestions_service.h',
         'suggestions/suggestions_store.cc',
         'suggestions/suggestions_store.h',
         'suggestions/suggestions_utils.cc',
         'suggestions/suggestions_utils.h',
       ],
       'variables': {
         'proto_in_dir': 'suggestions/proto',
         'proto_out_dir': 'components/suggestions/proto',
       },
       'includes': [ '../build/protoc.gypi' ],
     },
-  ],
+    # TODO(justincohen): iOS cannot depend on ui/gfx, so we should provide an
+    # implementation of the image encoder, and put this target in a block that
+    # excludes iOS.
+    {
+      # GN version: //components/suggestions:jpeg_image_encoder
+      'target_name': 'jpeg_image_encoder',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../ui/gfx/gfx.gyp:gfx',
+        'suggestions',
+      ],
+      'sources': [
+        'suggestions/jpeg/jpeg_image_encoder.cc',
+        'suggestions/jpeg/jpeg_image_encoder.h',
+      ],
+    }
+  ]
 }