Initialize key_pressed_.

Was resulting in an error on Mac Asan:
[ RUN      ] ApmTest.DebugDump
[libprotobuf FATAL ../../third_party/protobuf/src/google/protobuf/message_lite.cc:224] CHECK failed: !coded_out.HadError():

TBR=aluebs

Review URL: https://webrtc-codereview.appspot.com/8539004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5536 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.cc b/webrtc/modules/audio_processing/audio_processing_impl.cc
index 77f494f..3ca90a7 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl.cc
@@ -97,7 +97,8 @@
       was_stream_delay_set_(false),
       num_reverse_channels_(1),
       num_input_channels_(1),
-      num_output_channels_(1) {
+      num_output_channels_(1),
+      key_pressed_(false) {
   echo_cancellation_ = EchoCancellationImplWrapper::Create(this);
   component_list_.push_back(echo_cancellation_);