ui: Cleanup class/struct forward declarations

blimp/client/core/settings/android/java/src/org/chromium/blimp/core/settings/SettingsObserverProxy.java

Index: blimp/client/core/settings/android/java/src/org/chromium/blimp/core/settings/SettingsObserverProxy.java
diff --git a/blimp/client/core/settings/android/java/src/org/chromium/blimp/core/settings/SettingsObserverProxy.java b/blimp/client/core/settings/android/java/src/org/chromium/blimp/core/settings/SettingsObserverProxy.java
new file mode 100644
index 0000000000000000000000000000000000000000..c36afee791a42419462cfd5c2bff41543411c438
--- /dev/null
+++ b/blimp/client/core/settings/android/java/src/org/chromium/blimp/core/settings/SettingsObserverProxy.java
@@ -0,0 +1,76 @@
+// Copyright 2016 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.blimp.core.settings;
+
+import org.chromium.base.ObserverList;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+/**
+ * Serves as a compound observer proxy for dispatching SettingsObserver callbacks, avoiding
+ * redundant JNI-related work when there are multiple Java-based observers.
+ */
+@JNINamespace("blimp::client")
+class SettingsObserverProxy implements SettingsObserver {
+    private final ObserverList<SettingsObserver> mObservers = new ObserverList<>();
+
+    private long mNativeSettingsObserverProxy;
+
+    SettingsObserverProxy(Settings settings) {
+        mNativeSettingsObserverProxy = nativeInit(settings);
+    }
+
+    void destroy() {
+        if (mNativeSettingsObserverProxy != 0) {
+            nativeDestroy(mNativeSettingsObserverProxy);
+            mNativeSettingsObserverProxy = 0;
+        }
+        mObservers.clear();
+    }
+
+    void addObserver(SettingsObserver observer) {
+        assert mNativeSettingsObserverProxy != 0;
+        mObservers.addObserver(observer);
+    }
+
+    void removeObserver(SettingsObserver observer) {
+        mObservers.removeObserver(observer);
+    }
+
+    @Override
+    @CalledByNative
+    public void onBlimpModeEnabled(boolean enable) {
+        for (SettingsObserver observer : mObservers) {
+            observer.onBlimpModeEnabled(enable);
+        }
+    }
+
+    @Override
+    @CalledByNative
+    public void onShowNetworkStatsChanged(boolean enable) {
+        for (SettingsObserver observer : mObservers) {
+            observer.onShowNetworkStatsChanged(enable);
+        }
+    }
+
+    @Override
+    @CalledByNative
+    public void onRecordWholeDocumentChanged(boolean enable) {
+        for (SettingsObserver observer : mObservers) {
+            observer.onRecordWholeDocumentChanged(enable);
+        }
+    }
+
+    @Override
+    @CalledByNative
+    public void onRestartRequired() {
+        for (SettingsObserver observer : mObservers) {
+            observer.onRestartRequired();
+        }
+    }
+
+    private native long nativeInit(Settings settings);
+    private native void nativeDestroy(long nativeSettingsObserverProxy);
+}