Extract touchscreen device management into a generic manager

ui/events/BUILD.gn

Index: ui/events/BUILD.gn
diff --git a/ui/events/BUILD.gn b/ui/events/BUILD.gn
index e2fe42b84dd97aa35d2d461bbc7a2914f52f7dd7..8b8700c12043a1d8c10437bc23a4a3bde8e230d1 100644
--- a/ui/events/BUILD.gn
+++ b/ui/events/BUILD.gn
@@ -16,6 +16,8 @@ static_library("dom4_keycode_converter") {
 
 component("events_base") {
   sources = [
+    "device_data_manager.cc",
+    "device_data_manager.h",
     "event_constants.h",
     "event_switches.cc",
     "event_switches.h",
@@ -55,14 +57,16 @@ component("events_base") {
     sources += [
       "keycodes/keyboard_code_conversion_x.cc",
       "keycodes/keyboard_code_conversion_x.h",
-      "x/device_data_manager.cc",
-      "x/device_data_manager.h",
+      "x/device_data_manager_x11.cc",
+      "x/device_data_manager_x11.h",
       "x/device_list_cache_x.cc",
       "x/device_list_cache_x.h",
       "x/touch_factory_x11.cc",
       "x/touch_factory_x11.h",
     ]
   }
+
+  forward_dependent_configs_from = [ "//ui/gfx" ]

[sadrul, 2014/06/16 14:48:38]

What does this do? Should this be a separate change?

[dnicoara, 2014/06/16 15:16:00]

It's the GYP equivalent for export_dependent_settings. I was trying to have the
GN trybot happy as well.

[sadrul, 2014/06/17 20:37:08]

Can this be a separate CL? What change in this CL requires this?

[dnicoara, 2014/06/18 14:04:29]

Removed it from this CL.

The forward dependency was always needed, though, depending on the compile order
some of the targets, gfx would have already been included. 

device_data_manager.h uses gfx::Transform, thus targets depending on it will
need to link against gfx as well.

I feel pretty bad for breaking the GN build. IS GN a tree closer?

[sadrul, 2014/06/18 16:18:14]

The GN builder is tree closer, yes. You should add back the changes in
|sources|.

The current x11 device-manager uses gfx::Transform, but it doesn't need this
change (i.e. the change in |forward_dependent_configs_from| (and
|export_dependent_settings| in gyp)). So I am curious to know what changed in
this CL to require this.

[dnicoara, 2014/06/18 17:28:02]

ui/events/platform/x11 didn't use to create the DDM so it didn't need to depend
on events_base. ui/events/platform/x11 doesn't directly depend on gfx (unlike
most other targets) so it complains about missing definitions.

 }
 
 component("events") {