Disable encoder scaling on iPhone4S.

webrtc/modules/video_coding/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../../build/webrtc.gni")
 
@@ skipping 161 matching lines @@
       "//third_party/openh264:encoder",
     ]
   }
 }
 
 if (is_ios) {
   source_set("webrtc_h264_video_toolbox") {
     sources = [
       "codecs/h264/h264_video_toolbox_decoder.cc",
       "codecs/h264/h264_video_toolbox_decoder.h",
-      "codecs/h264/h264_video_toolbox_encoder.cc",
       "codecs/h264/h264_video_toolbox_encoder.h",
+      "codecs/h264/h264_video_toolbox_encoder.mm",
       "codecs/h264/h264_video_toolbox_nalu.cc",
       "codecs/h264/h264_video_toolbox_nalu.h",
     ]
 
     configs += [
       "../..:common_objc",
       "//build/config/compiler:enable_arc",
     ]
 
     deps = [
@@ skipping 138 matching lines @@
       # Suppress warnings from Chrome's Clang plugins.
       # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
       configs -= [ "//build/config/clang:find_bad_constructs" ]
     }
 
     deps = [
       "../../test:test_support",
     ]
   }
 }