[Device Service] Port ScreenOrientationListener into Device Service.

content/common/screen_orientation_messages.h

Index: content/common/screen_orientation_messages.h
diff --git a/content/common/screen_orientation_messages.h b/content/common/screen_orientation_messages.h
index fd456622f12c27f7b0edfb619bdfcbdf0ea2a352..c8d1177adb28a2b883df23d5331d4c32e13a4292 100644
--- a/content/common/screen_orientation_messages.h
+++ b/content/common/screen_orientation_messages.h
@@ -13,8 +13,6 @@
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 
-#define IPC_MESSAGE_START ScreenOrientationMsgStart

[blundell, 2017/03/09 16:48:20]

This bugfix is unrelated to the rest of this CL, correct? If so, I would split
it out into its own little CL.

[leonhsl(Using Gerrit), 2017/03/10 02:43:06]

Oh, this relates with this CL's work.
ScreenOrientationMsgStart was used to make a BrowserMessageFilter at line14 in
https://codereview.chromium.org/2745443002/diff/20001/content/browser/screen_...,
but now this CL decouples this file into Device Service and do not expect it to
be a BrowserMessageFilter, thus we can delete ScreenOrientationMsgStart here.

-
 // Only used by content/common/manifest_manager_messages.h.

[Tom Sepez, 2017/03/14 16:20:15]

Maybe we can delete this file entirely and move the one remaining trait to the
aforementioned file or content/common/content_param_traits_macros.h ?

[leonhsl(Using Gerrit), 2017/03/15 02:07:34]

Yeah I think we should do this. I'd like to prepare a follow-up CL for your
review, because it's somehow another different task with this one :)

 IPC_ENUM_TRAITS_MIN_MAX_VALUE(blink::WebScreenOrientationLockType,
                               blink::WebScreenOrientationLockDefault,