Enable starting window logging

Also extend it to make sure we catch the bug!

Test: Open a couple of cold/hot apps, make sure logs look accurate
Bug: 37888853
Change-Id: Ied394969748d4d2d40359af15e0b491a2dc2b078
diff --git a/services/core/java/com/android/server/wm/AppWindowToken.java b/services/core/java/com/android/server/wm/AppWindowToken.java
index 52eb2fb..17db253 100644
--- a/services/core/java/com/android/server/wm/AppWindowToken.java
+++ b/services/core/java/com/android/server/wm/AppWindowToken.java
@@ -38,6 +38,7 @@
 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_LAYOUT_REPEATS;
 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_ORIENTATION;
 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_STARTING_WINDOW;
+import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_STARTING_WINDOW_VERBOSE;
 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_TOKEN_MOVEMENT;
 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_VISIBILITY;
 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_WINDOW_MOVEMENT;
@@ -806,6 +807,8 @@
         } else if (mChildren.size() == 1 && startingSurface != null && !isRelaunching()) {
             // If this is the last window except for a starting transition window,
             // we need to get rid of the starting transition.
+            if (DEBUG_STARTING_WINDOW) Slog.v(TAG_WM, "Last window, removing starting window "
+                    + win);
             if (getController() != null) {
                 getController().removeStartingWindow();
             }
@@ -1372,7 +1375,7 @@
      *         windows in this app token where not considered drawn as of the last pass.
      */
     boolean updateDrawnWindowStates(WindowState w) {
-        if (DEBUG_STARTING_WINDOW && w == startingWindow) {
+        if (DEBUG_STARTING_WINDOW_VERBOSE && w == startingWindow) {
             Slog.d(TAG, "updateWindows: starting " + w + " isOnScreen=" + w.isOnScreen()
                     + " allDrawn=" + allDrawn + " freezingScreen=" + mAppAnimator.freezingScreen);
         }