Add ObjC API for getting native histograms.

webrtc/sdk/BUILD.gn

 # Copyright 2016 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")
 import("//build_overrides/webrtc.gni")
@@ skipping 10 matching lines @@
       "objc/Framework/Classes",
       "objc/Framework/Headers",
     ]
     sources = [
       "objc/Framework/Classes/NSString+StdString.h",
       "objc/Framework/Classes/NSString+StdString.mm",
       "objc/Framework/Classes/RTCCameraPreviewView.m",
       "objc/Framework/Classes/RTCDispatcher.m",
       "objc/Framework/Classes/RTCFieldTrials.mm",
       "objc/Framework/Classes/RTCLogging.mm",
+      "objc/Framework/Classes/RTCMetric+Private.h",
+      "objc/Framework/Classes/RTCMetric.mm",
       "objc/Framework/Classes/RTCSSLAdapter.mm",
       "objc/Framework/Classes/RTCTracing.mm",
       "objc/Framework/Classes/RTCUIApplication.h",
       "objc/Framework/Classes/RTCUIApplication.mm",
       "objc/Framework/Headers/WebRTC/RTCCameraPreviewView.h",
       "objc/Framework/Headers/WebRTC/RTCDispatcher.h",
       "objc/Framework/Headers/WebRTC/RTCFieldTrials.h",
       "objc/Framework/Headers/WebRTC/RTCLogging.h",
       "objc/Framework/Headers/WebRTC/RTCMacros.h",
+      "objc/Framework/Headers/WebRTC/RTCMetric.h",
       "objc/Framework/Headers/WebRTC/RTCSSLAdapter.h",
       "objc/Framework/Headers/WebRTC/RTCTracing.h",
     ]
     if (!build_with_chromium) {
       sources += [
         "objc/Framework/Classes/RTCFileLogger.mm",
         "objc/Framework/Headers/WebRTC/RTCFileLogger.h",
       ]
     }
     libs = [ "AVFoundation.framework" ]
@@ skipping 96 matching lines @@
     }
 
     if (is_mac) {
       sources += [
         "objc/Framework/Classes/RTCNSGLVideoView.m",
         "objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h",
       ]
     }
   }
 }