Update selection of resolution policy for screen capture with getUserMedia.

content/renderer/media/media_stream_constraints_util_video_content_unittest.cc

 // Copyright 2017 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.
 
 #include "content/renderer/media/media_stream_constraints_util_video_content.h"
 
 #include <cmath>
 #include <string>
 
 #include "content/renderer/media/mock_constraint_factory.h"
@@ skipping 1951 matching lines @@
     auto result = SelectSettings();
     EXPECT_EQ(std::round(480 * 1.32), result.Width());
     EXPECT_EQ(480, result.Height());
     // Exact aspect ratio prevents the resolution from being adjusted.
     EXPECT_EQ(media::RESOLUTION_POLICY_FIXED_RESOLUTION,
               result.ResolutionChangePolicy());
     EXPECT_EQ(1.32, result.track_adapter_settings().min_aspect_ratio);
     EXPECT_EQ(1.32, result.track_adapter_settings().max_aspect_ratio);
     CheckTrackAdapterSettingsEqualsFormat(result);
   }
+  {
+    constraint_factory_.Reset();
+    constraint_factory_.basic().height.SetMax(4000);
+    constraint_factory_.basic().width.SetMax(4000);
+    auto result = SelectSettings();
+    EXPECT_EQ(4000, result.Width());
+    EXPECT_EQ(4000, result.Height());
+    // Only specifying a maximum resolution allows resolution adjustment.
+    EXPECT_EQ(media::RESOLUTION_POLICY_ANY_WITHIN_LIMIT,
+              result.ResolutionChangePolicy());
+    EXPECT_EQ(1.0 / 4000, result.track_adapter_settings().min_aspect_ratio);
+    EXPECT_EQ(4000.0, result.track_adapter_settings().max_aspect_ratio);
+    CheckTrackAdapterSettingsEqualsFormat(result);
+  }
 }
 
 }  // namespace content