Clear IMM references when window dismissed.

Match behavior of removeViewLocked(), where InputMethodManager clears
any strong references to Views, and also clear mCurRootView. Without
this, IMM can leak a DecorView instance after the user has left the
application.

Bug: 6413553
Change-Id: Iad09cf5dbb7f6f156fd39ed243431432e00f8945

Author: jsharkey

core/java/android/view/WindowManagerImpl.java

@@ -340,6 +340,14 @@ public void removeViewImmediate(View view) {
             View curView = root.getView();
 
             root.mAddNesting = 0;
+
+            if (view != null) {
+                InputMethodManager imm = InputMethodManager.getInstance(view.getContext());
+                if (imm != null) {
+                    imm.windowDismissed(mViews[index].getWindowToken());
+                }
+            }
+
             root.die(true);
             finishRemoveViewLocked(curView, index);
             if (curView == view) {

core/java/android/view/inputmethod/InputMethodManager.java

@@ -672,6 +672,7 @@ void clearConnectionLocked() {
      * Disconnect any existing input connection, clearing the served view.
      */
     void finishInputLocked() {
+        mCurRootView = null;
         mNextServedView = null;
         if (mServedView != null) {
             if (DEBUG) Log.v(TAG, "FINISH INPUT: " + mServedView);