Reland of Android: support multiple displays on C++ side

ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java

Index: ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
diff --git a/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java b/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
index dd86c1e152987fb92f81c3f873db1459a87e09d8..c11b285c774ca2b449f81d7acff77acb557bb9c9 100644
--- a/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
+++ b/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
@@ -158,7 +158,11 @@ import org.chromium.ui.gfx.DeviceDisplayInfo;
 
         @Override
         public void onDisplayRemoved(int sdkDisplayId) {
-            mIdMap.remove(sdkDisplayId);
+            DisplayAndroid displayAndroid = mIdMap.get(sdkDisplayId);
+            if (displayAndroid != null) {
+                displayAndroid.onRemovedFromMap();
+                mIdMap.remove(sdkDisplayId);
+            }
         }
 
         @Override
@@ -238,6 +242,8 @@ import org.chromium.ui.gfx.DeviceDisplayInfo;
         int sdkDisplayId = display.getDisplayId();
         DisplayAndroid displayAndroid = new DisplayAndroid(display);
         mIdMap.put(sdkDisplayId, displayAndroid);
+
+        displayAndroid.onAddedToMap();
         return displayAndroid;
     }
 }