Merge changes from topic "malloc-purge-master"

* changes:
  hwui: purge malloc pages on bitmap destruction
  wm: recycle bitmaps immediately in TaskSnapshotPersister

libs/hwui/hwui/Bitmap.cpp

@@ -224,6 +224,7 @@ Bitmap::~Bitmap() {
             break;
         case PixelStorageType::Heap:
             free(mPixelStorage.heap.address);
+            mallopt(M_PURGE, 0);
             break;
         case PixelStorageType::Hardware:
             auto buffer = mPixelStorage.hardware.buffer;

services/core/java/com/android/server/wm/TaskSnapshotPersister.java

@@ -17,6 +17,7 @@
 package com.android.server.wm;
 
 import static android.graphics.Bitmap.CompressFormat.*;
+
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
 
@@ -361,6 +362,7 @@ class TaskSnapshotPersister {
 
             // For snapshots with reduced resolution, do not create or save full sized bitmaps
             if (mSnapshot.isReducedResolution()) {
+                swBitmap.recycle();
                 return true;
             }
 
@@ -373,6 +375,8 @@ class TaskSnapshotPersister {
                 Slog.e(TAG, "Unable to open " + file + " for persisting.", e);
                 return false;
             }
+            reduced.recycle();
+            swBitmap.recycle();
             return true;
         }
     }