WIP Handle AwContents needing multiple live functors.

android_webview/java/src/org/chromium/android_webview/AwGLFunctor.java

Index: android_webview/java/src/org/chromium/android_webview/AwGLFunctor.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwGLFunctor.java b/android_webview/java/src/org/chromium/android_webview/AwGLFunctor.java
index e50928373f088b7d58d5a5dc7742e14e0876a7bd..b9421ebae27345c0690b35ce41d15e4282b54984 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwGLFunctor.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwGLFunctor.java
@@ -7,6 +7,7 @@ package org.chromium.android_webview;
 import android.graphics.Canvas;
 import android.view.ViewGroup;
 
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ -44,6 +45,7 @@ public class AwGLFunctor {
     private final AwContents.NativeDrawGLFunctor mNativeDrawGLFunctor;
     private final ViewGroup mContainerView;
     private final Runnable mFunctorReleasedCallback;
+    private int mPinCount;

[boliu, 2016/05/17 15:00:10]

maybe just call this refcount, and make the method increase ref count and
decrease ref count or something like that?

[Tobias Sargeant, 2016/05/17 15:07:36]

I felt like this was overloading the phrase refcount - but if you prefer that,
sure.

[Tobias Sargeant, 2016/05/17 16:55:26]

Done.

 
     public AwGLFunctor(AwContents.NativeDrawGLFunctorFactory nativeDrawGLFunctorFactory,
             ViewGroup containerView) {
@@ -57,8 +59,7 @@ public class AwGLFunctor {
             mFunctorReleasedCallback = new Runnable() {
                 @Override
                 public void run() {
-                    // Deliberate no-op. This Runnable is holding a strong reference back to the
-                    // AwGLFunctor, which serves its purpose for now.
+                    unpinHardwareRenderer();
                 }
             };
         } else {
@@ -66,6 +67,21 @@ public class AwGLFunctor {
         }
     }
 
+    public synchronized void pinHardwareRenderer() {
+        ++mPinCount;
+    }
+
+    public synchronized void unpinHardwareRenderer() {
+        if (--mPinCount == 0) {
+            ThreadUtils.runOnUiThread(new Runnable() {

[boliu, 2016/05/17 15:00:10]

why post this?

[Tobias Sargeant, 2016/05/17 15:07:36]

The callback runs on the render thread, but we can only call
deleteHardwareRenderer on the UI thread. The unpin might come from either the UI
thread or the render thread, depending on the caller.

[boliu, 2016/05/17 15:09:43]

wait...... really?? that wasn't explicitly stated...

[Tobias Sargeant, 2016/05/17 16:55:26]

Checked, and the callback is run on the thread it is added on, so no need for
posts or synchronization. Hooray.

+                @Override
+                public void run() {
+                    deleteHardwareRenderer();
+                }
+            });
+        }
+    }
+
     public static long getAwDrawGLFunction() {
         return nativeGetAwDrawGLFunction();
     }
@@ -74,11 +90,10 @@ public class AwGLFunctor {
         return mNativeAwGLFunctor;
     }
 
-    public Object getNativeLifetimeObject() {
-        return mLifetimeObject;
-    }
-
-    public boolean requestDrawGLForCanvas(Canvas canvas) {
+    public boolean requestDrawGL(Canvas canvas) {
+        if (mFunctorReleasedCallback != null) {
+            pinHardwareRenderer();

[boliu, 2016/05/17 15:00:11]

pin only if requestDrawGL returns true, or if you really want to be safe, pin
before, and make sure to unpin if requestDrawGL returns false..

[Tobias Sargeant, 2016/05/17 16:55:25]

Done.

+        }
         return mNativeDrawGLFunctor.requestDrawGL(canvas, mFunctorReleasedCallback);
     }