Added a kEchoCancellation constraint to turn off the audio processing.

content/renderer/media/mock_media_constraint_factory.cc

 // Copyright 2014 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/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/renderer/media/mock_media_constraint_factory.h"
 #include "third_party/libjingle/source/talk/app/webrtc/mediaconstraintsinterface.h"
 
 namespace content {
@@ skipping 19 matching lines @@
                                                  base::IntToString16(value)));
 }
 
 void MockMediaConstraintFactory::AddMandatory(const std::string& key,
                                               double value) {
   mandatory_.push_back(blink::WebMediaConstraint(
       base::UTF8ToUTF16(key),
       base::UTF8ToUTF16(base::DoubleToString(value))));
 }
 
+void MockMediaConstraintFactory::AddMandatory(const std::string& key,
+                                              const std::string& value) {
+  mandatory_.push_back(blink::WebMediaConstraint(
+      base::UTF8ToUTF16(key), base::UTF8ToUTF16(value)));
+}
+
 void MockMediaConstraintFactory::AddOptional(const std::string& key,
                                              int value) {
   optional_.push_back(blink::WebMediaConstraint(base::UTF8ToUTF16(key),
                                                 base::IntToString16(value)));
 }
 
 void MockMediaConstraintFactory::AddOptional(const std::string& key,
                                              double value) {
   optional_.push_back(blink::WebMediaConstraint(
       base::UTF8ToUTF16(key),
       base::UTF8ToUTF16(base::DoubleToString(value))));
 }
 
+void MockMediaConstraintFactory::AddOptional(const std::string& key,
+                                             const std::string& value) {
+  optional_.push_back(blink::WebMediaConstraint(
+      base::UTF8ToUTF16(key), base::UTF8ToUTF16(value)));
+}
+
 void MockMediaConstraintFactory::DisableDefaultAudioConstraints() {
   static const char* kDefaultAudioConstraints[] = {
       webrtc::MediaConstraintsInterface::kEchoCancellation,
       webrtc::MediaConstraintsInterface::kExperimentalEchoCancellation,
       webrtc::MediaConstraintsInterface::kAutoGainControl,
       webrtc::MediaConstraintsInterface::kExperimentalAutoGainControl,
       webrtc::MediaConstraintsInterface::kNoiseSuppression,
       webrtc::MediaConstraintsInterface::kHighpassFilter,
       webrtc::MediaConstraintsInterface::kTypingNoiseDetection,
       webrtc::MediaConstraintsInterface::kExperimentalNoiseSuppression
   };
   MockMediaConstraintFactory factory;
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kDefaultAudioConstraints); ++i) {
     AddMandatory(kDefaultAudioConstraints[i], false);
   }
 }
 
 }  // namespace content