Make input system aware of multiple displays.

The input system needs to know about the window that has
focus, even if it is on a secondary display.  So now we
send it the list of all windows and indicate which display
they are on.  We filter the list of windows as necessary
when delivering touch events.

To keep things simple, monitor input channels and input
filters are not supported except on the main display.
We also do not pass the display id to applications; it is
only used inside the input system for now.

Properly scale touch coordinates based on the viewport.
This will be needed to ensure that touch works on external
display as well as when the internal display is being used
to simulate a different resolution.

Change-Id: I1815579a52fcc852c519b5391fc7ab8767c2dc59
diff --git a/services/input/InputListener.cpp b/services/input/InputListener.cpp
index 657a6b9..c2705b0 100644
--- a/services/input/InputListener.cpp
+++ b/services/input/InputListener.cpp
@@ -69,12 +69,12 @@
 NotifyMotionArgs::NotifyMotionArgs(nsecs_t eventTime, int32_t deviceId, uint32_t source,
         uint32_t policyFlags,
         int32_t action, int32_t flags, int32_t metaState, int32_t buttonState,
-        int32_t edgeFlags, uint32_t pointerCount,
+        int32_t edgeFlags, int32_t displayId, uint32_t pointerCount,
         const PointerProperties* pointerProperties, const PointerCoords* pointerCoords,
         float xPrecision, float yPrecision, nsecs_t downTime) :
         eventTime(eventTime), deviceId(deviceId), source(source), policyFlags(policyFlags),
         action(action), flags(flags), metaState(metaState), buttonState(buttonState),
-        edgeFlags(edgeFlags), pointerCount(pointerCount),
+        edgeFlags(edgeFlags), displayId(displayId), pointerCount(pointerCount),
         xPrecision(xPrecision), yPrecision(yPrecision), downTime(downTime) {
     for (uint32_t i = 0; i < pointerCount; i++) {
         this->pointerProperties[i].copyFrom(pointerProperties[i]);
@@ -87,7 +87,8 @@
         policyFlags(other.policyFlags),
         action(other.action), flags(other.flags),
         metaState(other.metaState), buttonState(other.buttonState),
-        edgeFlags(other.edgeFlags), pointerCount(other.pointerCount),
+        edgeFlags(other.edgeFlags), displayId(other.displayId),
+        pointerCount(other.pointerCount),
         xPrecision(other.xPrecision), yPrecision(other.yPrecision), downTime(other.downTime) {
     for (uint32_t i = 0; i < pointerCount; i++) {
         pointerProperties[i].copyFrom(other.pointerProperties[i]);