Use explicit WebString conversion methods in content/renderer/media (unittests)

content/renderer/media/media_stream_video_capturer_source_unittest.cc

Index: content/renderer/media/media_stream_video_capturer_source_unittest.cc
diff --git a/content/renderer/media/media_stream_video_capturer_source_unittest.cc b/content/renderer/media/media_stream_video_capturer_source_unittest.cc
index abe18be547acfc5f37ec71eb124fd5aa2a2d02c5..89129612ce246e0466e36dce5ea878c37f93764e 100644
--- a/content/renderer/media/media_stream_video_capturer_source_unittest.cc
+++ b/content/renderer/media/media_stream_video_capturer_source_unittest.cc
@@ -83,9 +83,9 @@ class MediaStreamVideoCapturerSourceTest : public testing::Test {
         std::move(delegate));
     source_->SetDeviceInfo(device_info);
 
-    webkit_source_.initialize(base::UTF8ToUTF16("dummy_source_id"),
+    webkit_source_.initialize(blink::WebString::fromASCII("dummy_source_id"),
                               blink::WebMediaStreamSource::TypeVideo,
-                              base::UTF8ToUTF16("dummy_source_name"),
+                              blink::WebString::fromASCII("dummy_source_name"),
                               false /* remote */);
     webkit_source_.setExtraData(source_);
     webkit_source_id_ = webkit_source_.id();
@@ -298,9 +298,9 @@ TEST_F(MediaStreamVideoCapturerSourceTest, Ended) {
       base::Bind(&MediaStreamVideoCapturerSourceTest::OnSourceStopped,
                  base::Unretained(this)),
       std::move(delegate));
-  webkit_source_.initialize(base::UTF8ToUTF16("dummy_source_id"),
+  webkit_source_.initialize(blink::WebString::fromASCII("dummy_source_id"),
                             blink::WebMediaStreamSource::TypeVideo,
-                            base::UTF8ToUTF16("dummy_source_name"),
+                            blink::WebString::fromASCII("dummy_source_name"),
                             false /* remote */);
   webkit_source_.setExtraData(source_);
   webkit_source_id_ = webkit_source_.id();