Always send BOUNDS_CHANGE_REASON_PIP for PIP windows

Although PIP windows are not supposed to be resized by Chrome,
because of vaious off-by-one issues, some bounds move events for
PIP windows are currently considered to be
BOUNDS_CHANGE_REASON_RESIZE, and Android rejects those events as
the window is already in PIP.

BUG=b:171361297
TEST=Manually confirmed the bounds of PIP matches between Android and Chrome

Change-Id: I62d2909f32143e5369587de2ea8abf5748b82233
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2488263
Commit-Queue: Kazuki Takise <takise@chromium.org>
Auto-Submit: Kazuki Takise <takise@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819802}

components/exo/wayland/zcr_remote_shell.cc

@@ -1143,11 +1143,10 @@ class WaylandRemoteShell : public ash::TabletModeObserver,
       int bounds_change) {
     zcr_remote_surface_v1_bounds_change_reason reason =
         ZCR_REMOTE_SURFACE_V1_BOUNDS_CHANGE_REASON_RESIZE;
-    if (!resize) {
-      reason = current_state == WindowStateType::kPip
-                   ? ZCR_REMOTE_SURFACE_V1_BOUNDS_CHANGE_REASON_MOVE_PIP
-                   : ZCR_REMOTE_SURFACE_V1_BOUNDS_CHANGE_REASON_MOVE;
-    }
+    if (!resize)
+      reason = ZCR_REMOTE_SURFACE_V1_BOUNDS_CHANGE_REASON_MOVE;
+    if (current_state == WindowStateType::kPip)
+      reason = ZCR_REMOTE_SURFACE_V1_BOUNDS_CHANGE_REASON_PIP;
     if (bounds_change & ash::WindowResizer::kBoundsChange_Resizes) {
       reason = ZCR_REMOTE_SURFACE_V1_BOUNDS_CHANGE_REASON_DRAG_RESIZE;
     } else if (bounds_change & ash::WindowResizer::kBoundsChange_Repositions) {

third_party/wayland-protocols/unstable/remote-shell/remote-shell-unstable-v1.xml

@@ -734,7 +734,7 @@
 	     summary="the window bounds is moved due to other WM operations"/>
       <entry name="resize" value="6"
 	     summary="the window bounds is reiszed due to other WM operations"/>
-      <entry name="move_pip" value="7" summary="the window bounds is resized for PIP"/>
+      <entry name="pip" value="7" summary="the window bounds is resized or moved for PIP"/>
     </enum>
 
     <event name="bounds_changed" since="10">