Turn audio ducking on by default on Windows again.

content/renderer/media/media_stream_audio_processor_unittest.cc

 // Copyright 2013 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 "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/aligned_memory.h"
 #include "base/path_service.h"
@@ skipping 318 matching lines @@
     constraint_factory.AddOptional(MediaAudioConstraints::kEchoCancellation,
                                    false);
     blink::WebMediaConstraints constraints =
         constraint_factory.CreateWebMediaConstraints();
     MediaAudioConstraints audio_constraints(constraints, 0);
     for (size_t i = 0; i < arraysize(kDefaultAudioConstraints); ++i) {
       EXPECT_FALSE(audio_constraints.GetProperty(kDefaultAudioConstraints[i]));
     }
     EXPECT_FALSE(audio_constraints.NeedsAudioProcessing());
 #if defined(OS_WIN)
-    // TODO(tommi): Turn this back to EXPECT_TRUE on Windows when ducking issues
-    // have been resolved.
-    // Bugs: crbug/391414, crbug/391247.
-    EXPECT_FALSE(audio_constraints.GetProperty(kMediaStreamAudioDucking));
+    EXPECT_TRUE(audio_constraints.GetProperty(kMediaStreamAudioDucking));
 #else
     EXPECT_FALSE(audio_constraints.GetProperty(kMediaStreamAudioDucking));
 #endif
   }
 }
 
 TEST_F(MediaStreamAudioProcessorTest, ValidateConstraints) {
   MockMediaConstraintFactory constraint_factory;
   const std::string dummy_constraint = "dummy";
   constraint_factory.AddMandatory(dummy_constraint, true);
@@ skipping 113 matching lines @@
     EXPECT_EQ(output_bus->channel(0)[0], 0);
     EXPECT_NE(output_bus->channel(1)[0], 0);
   }
 
   // Set |audio_processor| to NULL to make sure |webrtc_audio_device| outlives
   // |audio_processor|.
   audio_processor = NULL;
 }
 
 }  // namespace content