aw: Use functor callback for lifetime management

android_webview/glue/java/src/com/android/webview/chromium/DrawGLFunctor.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package com.android.webview.chromium;
 
 import android.graphics.Canvas;
+import android.os.Build;
 import android.view.View;
 
 import com.android.webview.chromium.WebViewDelegateFactory.WebViewDelegate;
 
 import org.chromium.content.common.CleanupReference;
 
 /**
  * Simple Java abstraction and wrapper for the native DrawGLFunctor flow.
  * An instance of this class can be constructed, bound to a single view context (i.e. AwContennts)
  * and then drawn and detached from the view tree any number of times (using requestDrawGL and
@@ skipping 27 matching lines @@
             mContainerView = null;
         }
     }
 
     public void detach() {
         if (mWebViewDelegate != null && mContainerView != null) {
             mWebViewDelegate.detachDrawGlFunctor(mContainerView, mNativeDrawGLFunctor);
         }
     }
 
-    public boolean requestDrawGL(Canvas canvas, View containerView, boolean waitForCompletion) {
+    private static final boolean sSupportFunctorReleasedCallback =
+            (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) || "N".equals(Build.VERSION.CODENAME);
+    public boolean requestDrawGL(Canvas canvas, View containerView, boolean waitForCompletion,
+            Runnable releasedCallback) {
         if (mDestroyRunnable.mNativeDrawGLFunctor == 0) {
             throw new RuntimeException("requested DrawGL on already destroyed DrawGLFunctor");
         }
 
         if (canvas != null && waitForCompletion) {
             throw new IllegalArgumentException(
                     "requested a blocking DrawGL with a not null canvas.");
         }
 
         if (!mWebViewDelegate.canInvokeDrawGlFunctor(containerView)) {
             return false;
         }
 
         mContainerView = containerView;
 
         if (canvas == null) {
+            assert releasedCallback == null;
             mWebViewDelegate.invokeDrawGlFunctor(
                     containerView, mDestroyRunnable.mNativeDrawGLFunctor, waitForCompletion);
             return true;
         }
 
-        mWebViewDelegate.callDrawGlFunction(canvas, mDestroyRunnable.mNativeDrawGLFunctor);
+        if (sSupportFunctorReleasedCallback) {
+            assert releasedCallback != null;
+            mWebViewDelegate.callDrawGlFunction(
+                    canvas, mDestroyRunnable.mNativeDrawGLFunctor, releasedCallback);
+        } else {
+            assert releasedCallback == null;
+            mWebViewDelegate.callDrawGlFunction(canvas, mDestroyRunnable.mNativeDrawGLFunctor);
+        }
         return true;
     }
 
+    public static boolean supportsDrawGLFunctorReleasedCallback() {
+        return sSupportFunctorReleasedCallback;
+    }
+
     public static void setChromiumAwDrawGLFunction(long functionPointer) {
         nativeSetChromiumAwDrawGLFunction(functionPointer);
     }
 
     // Holds the core resources of the class, everything required to correctly cleanup.
     // IMPORTANT: this class must not hold any reference back to the outer DrawGLFunctor
     // instance, as that will defeat GC of that object.
     private static final class DestroyRunnable implements Runnable {
         private long mNativeDrawGLFunctor;
         DestroyRunnable(long nativeDrawGLFunctor) {
             mNativeDrawGLFunctor = nativeDrawGLFunctor;
             assert mNativeDrawGLFunctor != 0;
         }
 
         // Called when the outer DrawGLFunctor instance has been GC'ed, i.e this is its finalizer.
         @Override
         public void run() {
             assert mNativeDrawGLFunctor != 0;
             nativeDestroyGLFunctor(mNativeDrawGLFunctor);
             mNativeDrawGLFunctor = 0;
         }
     }
 
     private static native long nativeCreateGLFunctor(long viewContext);
     private static native void nativeDestroyGLFunctor(long functor);
     private static native void nativeSetChromiumAwDrawGLFunction(long functionPointer);
 }