Upstream changes for NetworkQualityProvider

chrome/android/java/src/org/chromium/chrome/browser/net/qualityprovider/NetworkQualityProvider.java

Index: chrome/android/java/src/org/chromium/chrome/browser/net/qualityprovider/NetworkQualityProvider.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/net/qualityprovider/NetworkQualityProvider.java b/chrome/android/java/src/org/chromium/chrome/browser/net/qualityprovider/NetworkQualityProvider.java
new file mode 100644
index 0000000000000000000000000000000000000000..c433237f149e0146f2c4c0b98a0488f2cfc8bac8
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/net/qualityprovider/NetworkQualityProvider.java
@@ -0,0 +1,95 @@
+// Copyright 2015 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.net.qualityprovider;
+
+import android.content.Context;
+
+import org.chromium.chrome.browser.util.NonThreadSafe;
+
+/**
+ * This class provides a base class implementation and may be overridden on operating systems that
+ * provide more useful APIs. This class is not thread safe.
+ */
+public class NetworkQualityProvider {
+    private static NetworkQualityProvider sInstance = null;
+    private static NonThreadSafe sThreadCheck = null;
+
+    /**
+     * Value to return if a valid value is unavailable.
+     */
+    protected static final int NO_VALUE = -1;
+
+    /**
+     * Returns an instance of singleton NetworkQualityProvider.
+     */
+    public static NetworkQualityProvider getInstance() {
+        if (sThreadCheck == null) sThreadCheck = new NonThreadSafe();
+        assert sThreadCheck.calledOnValidThread();
+        if (sInstance == null) sInstance = new NetworkQualityProvider();
+        return sInstance;
+    }
+
+    /**
+     * Creates an instance of NetworkQualityProvider.
+     */
+    protected NetworkQualityProvider() {
+        assertCorrectness();
+    }
+
+    /**
+     * Initializes the provider with the context.
+     */
+    public void initialize(Context context) {

[nyquist, 2015/07/22 14:46:59]

Why not pass this context in to the constructor instead?

[tbansal1, 2015/07/22 21:11:29]

Done.

+        assertCorrectness();
+    }
+
+    /**
+     * Returns true if the network quality estimate is available.
+     */
+    protected boolean isEstimateAvailable() {
+        assertCorrectness();
+        return false;
+    }
+
+    /**
+     * Returns the expected RTT duration in milliseconds.
+     * Returns 0 if the estimate is unavailable.
+     */
+    protected int getRTTMilliseconds() {
+        assertCorrectness();
+        return NO_VALUE;
+    }
+
+    /**
+     * Returns the expected downstream throughput in Kbps.
+     * Returns 0 if the estimate is unavailable.
+     */
+    protected long getDownstreamThroughputKbps() {
+        assertCorrectness();
+        return NO_VALUE;
+    }
+
+    /**
+     * Returns the expected upstream throughput in Kbps.
+     * Returns 0 if the estimate is unavailable.
+     */
+    protected long getUpstreamThroughputKbps() {
+        assertCorrectness();
+        return NO_VALUE;
+    }
+
+    /**
+     * Returns time (in seconds) since the network quality was last updated.
+     */
+    protected long getTimeSinceLastUpdateSeconds() {
+        assertCorrectness();
+        return NO_VALUE;
+    }
+
+    private void assertCorrectness() {

[nyquist, 2015/07/22 14:46:59]

static?

[tbansal1, 2015/07/22 21:11:29]

Obsolete.

+        assert sThreadCheck.calledOnValidThread();
+        assert sInstance != null;
+    }
+}