Enable pinch-zoom telemetry on Mac

content/content_browser.gypi

 # Copyright (c) 2012 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base_static',
     '../components/url_formatter/url_formatter.gyp:url_formatter',
     '../crypto/crypto.gyp:crypto',
     '../device/battery/battery.gyp:device_battery',
@@ skipping 1181 matching lines @@
       'browser/renderer_host/input/synthetic_gesture.h',
       'browser/renderer_host/input/synthetic_gesture_controller.cc',
       'browser/renderer_host/input/synthetic_gesture_controller.h',
       'browser/renderer_host/input/synthetic_gesture_target.h',
       'browser/renderer_host/input/synthetic_gesture_target_android.cc',
       'browser/renderer_host/input/synthetic_gesture_target_android.h',
       'browser/renderer_host/input/synthetic_gesture_target_aura.cc',
       'browser/renderer_host/input/synthetic_gesture_target_aura.h',
       'browser/renderer_host/input/synthetic_gesture_target_base.cc',
       'browser/renderer_host/input/synthetic_gesture_target_base.h',
+      'browser/renderer_host/input/synthetic_gesture_target_mac.mm',
+      'browser/renderer_host/input/synthetic_gesture_target_mac.h',
       'browser/renderer_host/input/synthetic_pinch_gesture.cc',
       'browser/renderer_host/input/synthetic_pinch_gesture.h',
+      'browser/renderer_host/input/synthetic_touchpad_pinch_gesture.cc',
+      'browser/renderer_host/input/synthetic_touchpad_pinch_gesture.h',
+      'browser/renderer_host/input/synthetic_touchscreen_pinch_gesture.cc',
+      'browser/renderer_host/input/synthetic_touchscreen_pinch_gesture.h',
       'browser/renderer_host/input/synthetic_smooth_drag_gesture.cc',
       'browser/renderer_host/input/synthetic_smooth_drag_gesture.h',
       'browser/renderer_host/input/synthetic_smooth_move_gesture.cc',
       'browser/renderer_host/input/synthetic_smooth_move_gesture.h',
       'browser/renderer_host/input/synthetic_smooth_scroll_gesture.cc',
       'browser/renderer_host/input/synthetic_smooth_scroll_gesture.h',
       'browser/renderer_host/input/synthetic_tap_gesture.cc',
       'browser/renderer_host/input/synthetic_tap_gesture.h',
       'browser/renderer_host/input/tap_suppression_controller.cc',
       'browser/renderer_host/input/tap_suppression_controller.h',
@@ skipping 960 matching lines @@
     ['enable_webvr==1 and OS=="android"', {
       'sources': [
         'browser/vr/android/cardboard/cardboard_vr_device.cc',
         'browser/vr/android/cardboard/cardboard_vr_device.h',
         'browser/vr/android/cardboard/cardboard_vr_device_provider.cc',
         'browser/vr/android/cardboard/cardboard_vr_device_provider.h',
       ],
     }],
   ],
 }