Move blink scheduler implementation into a component

content/browser/DEPS

 include_rules = [
+  # Allow inclusion of specific components that we depend on. We may only
+  # depend on components which we share with the mojo html_viewer.
+  "+components/scheduler/common",
+  "+components/tracing",
+
   "+content/app/strings/grit",  # For generated headers
   "+content/public/browser",
   "+device/battery",  # For battery status service.
   "+device/vibration",  # For Vibration API
   "+media/audio",  # For audio input for speech input feature.
   "+media/base",  # For Android JNI registration.
   "+media/filters",  # For reporting GPU decoding UMA.
   "+media/midi",  # For Web MIDI API
   "+media/mojo",  # For mojo media services.
   "+media/video",  # For Video Device monitoring in Mac.
   "+mojo",
   "+sql",
   "+ui/aura_extra",
   "+ui/webui",
   "+win8/util",
 
-  # TODO(joi): This was misplaced; need to move it somewhere else,
-  # since //content shouldn't depend on //components, which is a layer
-  # above.
-  "+components/tracing",
-
   # In general, //content shouldn't depend on //device.
   # This is the an exception.
   "+device/udev_linux",  # For udev utility and wrapper library.
 
   # Other libraries.
   "+third_party/iaccessible2",
   "+third_party/isimpledom",
   "+third_party/khronos",   # For enum definitions only
   "+third_party/power_gadget",
   "+third_party/speex",
@@ skipping 49 matching lines @@
   "+third_party/WebKit/public/web/WebTextDirection.h",
   "+third_party/WebKit/public/web/WebTextInputType.h",
 
   # These should be burned down. http://crbug.com/237267
   "!third_party/WebKit/public/web/mac/WebInputEventFactory.h",
 
   # DO NOT ADD ANY CHROME OR COMPONENTS INCLUDES HERE!!!
   # See https://sites.google.com/a/chromium.org/dev/developers/content-module
   # for more information.
 ]