predictors: Make the resource_prefetch_predictor accessible from Java.

chrome/android/java/src/org/chromium/chrome/browser/customtabs/ResourcePrefetchPredictor.java

Index: chrome/android/java/src/org/chromium/chrome/browser/customtabs/ResourcePrefetchPredictor.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/ResourcePrefetchPredictor.java b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/ResourcePrefetchPredictor.java
new file mode 100644
index 0000000000000000000000000000000000000000..9673f4933c0a8a61dbce008c56e46e7fc6d707e8
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/ResourcePrefetchPredictor.java
@@ -0,0 +1,71 @@
+// 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.chrome.browser.customtabs;
+
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.chrome.browser.profiles.Profile;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Interface to the resource prefetch predictor.
+ *
+ * This allows to initiate and abort prefetches of likely subresources, based on
+ * the local browsing history.
+ */
+@JNINamespace("predictors")
+class ResourcePrefetchPredictor {
+    private ResourcePrefetchPredictor(long nativePointer) {
+        mNativePtr = nativePointer;
+    }
+
+    private static Map<Profile, ResourcePrefetchPredictor> sServiceMap;
+
+    /**
+     * @return a ResourcePrefetchPredictor for a given profile.
+     *
+     * If the predictor is not enabled, the object returned will not actually trigger any prefetch.
+     */
+    public static ResourcePrefetchPredictor getForProfile(Profile profile) {
+        ThreadUtils.assertOnUiThread();
+        if (sServiceMap == null) sServiceMap = new HashMap<Profile, ResourcePrefetchPredictor>();

[gone, 2016/09/28 18:18:15]

new HashMap<>():

[Benoit L, 2016/10/03 09:42:05]

Done.

+
+        ResourcePrefetchPredictor result = sServiceMap.get(profile);
+        if (result == null) {
+            long nativePtr = nativeGetResourcePrefetchPredictorForProfile(profile);
+            result = new ResourcePrefetchPredictor(nativePtr);
+            sServiceMap.put(profile, result);
+        }
+        return result;
+    }
+
+    /**
+     * Starts a prefetch for a URL.
+     *
+     * @param url The URL to start the prefetch for.
+     */
+    public void startPrefetching(String url) {
+        nativeStartPrefetching(mNativePtr, url);
+    }
+
+    /**
+     * Stops a prefetch for a URL, if one is in progress.
+     *
+     * @param url The URL to stop the prefetch of.
+     */
+    public void stopPrefetching(String url) {
+        nativeStopPrefetching(mNativePtr, url);
+    }
+
+    private long mNativePtr;
+
+    private static native long nativeGetResourcePrefetchPredictorForProfile(Profile profile);
+    private native void nativeStartPrefetching(
+            long nativeResourcePrefetchPredictorAndroid, String url);
+    private native void nativeStopPrefetching(
+            long nativeResourcePrefetchPredictorAndroid, String url);
+}