Adding key press detection in the browser process.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index c51b5c59122b17c8683a850d7e63840b7b9bc5a7..4194aa859c5d79ef18468597fc3f05492a1f4eed 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -52,6 +52,7 @@
 #include "crypto/nss_util.h"
 #include "media/audio/audio_manager.h"
 #include "media/base/media.h"
+#include "media/base/user_input_monitor.h"
 #include "media/midi/midi_manager.h"
 #include "net/base/network_change_notifier.h"
 #include "net/socket/client_socket_factory.h"
@@ -872,6 +873,14 @@ int BrowserMainLoop::BrowserThreadsStarted() {
         audio_manager_.get(), media_stream_manager_.get()));
   }
 
+  {
+    TRACE_EVENT0(
+        "startup",
+        "BrowserMainLoop::BrowserThreadsStarted::InitUserInputMonitor");
+    user_input_monitor_ = media::UserInputMonitor::Create(
+        io_thread_->message_loop_proxy(), main_thread_->message_loop_proxy());
+  }
+
   // Alert the clipboard class to which threads are allowed to access the
   // clipboard:
   std::vector<base::PlatformThreadId> allowed_clipboard_threads;