Receive app notifications in SimpleCache, so we save our index file

net/android/java/src/org/chromium/net/SimpleCacheActivityStatusNotifier.java

Index: net/android/java/src/org/chromium/net/SimpleCacheActivityStatusNotifier.java
diff --git a/net/android/java/src/org/chromium/net/SimpleCacheActivityStatusNotifier.java b/net/android/java/src/org/chromium/net/SimpleCacheActivityStatusNotifier.java
new file mode 100644
index 0000000000000000000000000000000000000000..c9882fd574307fd35344a9494f27254bcb3edac4
--- /dev/null
+++ b/net/android/java/src/org/chromium/net/SimpleCacheActivityStatusNotifier.java
@@ -0,0 +1,72 @@
+// Copyright (c) 2013 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 org.chromium.net;
+
+import android.util.Log;
+
+import org.chromium.base.ActivityStatus;
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+import org.chromium.base.NativeClassQualifiedName;
+
+import android.os.Handler;
+import android.os.Looper;
+
+/**
+ * Used by the SimpleIndex in net/disk_cache/simple/ to listen to changes in the android app state
+ * such as the app going to the background or foreground.
+ */
+public class SimpleCacheActivityStatusNotifier implements ActivityStatus.StateListener {
+    private int mNativePtr = 0;
+    private final Looper mIoLooper;
+
+    @CalledByNative
+    public static SimpleCacheActivityStatusNotifier newInstance(int nativePtr) {
+        return new SimpleCacheActivityStatusNotifier(nativePtr);
+    }
+
+    private SimpleCacheActivityStatusNotifier(int nativePtr) {
+        this.mIoLooper = Looper.myLooper();

[gavinp, 2013/04/25 08:28:27]

Since the construction comes from the net thread (typically the Chrome IO
thread), there's guaranteed to be no native looper. So this code makes Chrome
crash on any activity state change notification on Android.

When we make our next upload on this, let's make sure to add an android browser
test that receives at least one activity status notification.

+        this.mNativePtr = nativePtr;
+        // Call the singleton's ActivityStatus in the UI thread.
+        new Handler(Looper.getMainLooper()).post(new Runnable() {
+            @Override
+            public void run() {
+                ActivityStatus.registerStateListener(SimpleCacheActivityStatusNotifier.this);
+            }
+        });
+    }
+
+    @CalledByNative
+    public void prepareToBeDestroyed() {
+        this.mNativePtr = 0;
+        // Call the singleton's ActivityStatus in the UI thread.
+        new Handler(Looper.getMainLooper()).post(new Runnable() {
+            @Override
+            public void run() {
+                ActivityStatus.unregisterStateListener(SimpleCacheActivityStatusNotifier.this);
+            }
+        });
+    }
+
+    // ActivityStatus.StateListener
+    @Override
+    public void onActivityStateChange(final int state) {
+        if (state == ActivityStatus.RESUMED ||
+            state == ActivityStatus.STOPPED) {
+            new Handler(mIoLooper).post(new Runnable() {
+                @Override
+                public void run() {
+                    if (SimpleCacheActivityStatusNotifier.this.mNativePtr != 0)
+                        nativeNotifyActivityStatusChanged(
+                            SimpleCacheActivityStatusNotifier.this.mNativePtr, state);
+                }
+            });
+        }
+    }
+
+    @NativeClassQualifiedName("net::SimpleCacheActivityStatusNotifier")
+    private native void nativeNotifyActivityStatusChanged(int nativePtr, int newActivityStatus);
+}