Revert of Remove MediaStreamTrack.getSources().

components/test_runner/mock_web_user_media_client.cc

Index: components/test_runner/mock_web_user_media_client.cc
diff --git a/components/test_runner/mock_web_user_media_client.cc b/components/test_runner/mock_web_user_media_client.cc
index 3eace861e01485854accfc885643644b0eeed7f9..bc4e1bba4f93de639cfd361ce42ddbd23213900f 100644
--- a/components/test_runner/mock_web_user_media_client.cc
+++ b/components/test_runner/mock_web_user_media_client.cc
@@ -16,6 +16,8 @@
 #include "third_party/WebKit/public/platform/WebMediaStream.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamTrackSourcesRequest.h"
+#include "third_party/WebKit/public/platform/WebSourceInfo.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebMediaDevicesRequest.h"
@@ -27,6 +29,8 @@
 using blink::WebMediaStream;
 using blink::WebMediaStreamSource;
 using blink::WebMediaStreamTrack;
+using blink::WebMediaStreamTrackSourcesRequest;
+using blink::WebSourceInfo;
 using blink::WebString;
 using blink::WebUserMediaRequest;
 using blink::WebVector;
@@ -147,6 +151,41 @@
     media_device_change_observer_.didChangeMediaDevices();
 }
 
+void MockWebUserMediaClient::requestSources(
+    const blink::WebMediaStreamTrackSourcesRequest& request) {
+  struct {
+    const char* id;
+    WebSourceInfo::SourceKind kind;
+    const char* label;
+    WebSourceInfo::VideoFacingMode facing;
+  } test_sources[] = {
+    {
+      "device1",
+      WebSourceInfo::SourceKindAudio,
+      "Built-in microphone",
+      WebSourceInfo::VideoFacingModeNone,
+    },
+    {
+      "device2",
+      WebSourceInfo::SourceKindVideo,
+      "Build-in webcam",
+      WebSourceInfo::VideoFacingModeEnvironment,
+    },
+  };
+
+  WebVector<WebSourceInfo> sources(arraysize(test_sources));
+  for (size_t i = 0; i < arraysize(test_sources); ++i) {
+  sources[i].initialize(WebString::fromUTF8(test_sources[i].id),
+                        test_sources[i].kind,
+                        WebString::fromUTF8(test_sources[i].label),
+                        test_sources[i].facing);
+  }
+
+  delegate_->PostTask(base::Bind(
+      &WebMediaStreamTrackSourcesRequest::requestSucceeded,
+      base::Owned(new WebMediaStreamTrackSourcesRequest(request)), sources));
+}
+
 void MockWebUserMediaClient::setMediaDeviceChangeObserver(
     const blink::WebMediaDeviceChangeObserver& observer) {
   media_device_change_observer_ = observer;