Add API for new Cronet metrics

components/cronet/android/java/src/org/chromium/net/impl/CronetMetrics.java

+// 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.net.impl;
+
+import android.support.annotation.Nullable;
+
+import org.chromium.base.VisibleForTesting;
+import org.chromium.net.RequestFinishedInfo;
+
+import java.util.Date;
+
+@VisibleForTesting
+public final class CronetMetrics extends RequestFinishedInfo.Metrics {
+    private final long mProxyStartMs;
+    private final long mProxyEndMs;
+    private final long mDnsStartMs;
+    private final long mDnsEndMs;
+    private final long mConnectStartMs;
+    private final long mConnectEndMs;
+    private final long mSslStartMs;
+    private final long mSslEndMs;
+    private final long mSendingStartMs;
+    private final long mSendingEndMs;
+    private final long mPushStartMs;
+    private final long mPushEndMs;
+    private final long mResponseStartMs;
+    private final long mResponseEndMs;
+    private final boolean mSocketReused;
+
+    @Nullable
+    private final Long mTtfbMs;
+    @Nullable
+    private final Long mTotalTimeMs;
+    @Nullable
+    private final Long mSentBytesCount;
+    @Nullable
+    private final Long mReceivedBytesCount;
+
+    @Nullable
+    private static Date toDate(long timestamp) {
+        if (timestamp != 0) {
+            return new Date(timestamp);
+        }
+        return null;
+    }
+
+    /**
+     * Old-style constructor

[xunjieli, 2016/09/01 22:17:42]

Is this going away?
Should we add a TODO here so it's clearer?

[mgersh, 2016/09/02 19:32:08]

Done.

+     */
+    public CronetMetrics(@Nullable Long ttfbMs, @Nullable Long totalTimeMs,
+            @Nullable Long sentBytesCount, @Nullable Long receivedBytesCount) {
+        mTtfbMs = ttfbMs;
+        mTotalTimeMs = totalTimeMs;
+        mSentBytesCount = sentBytesCount;
+        mReceivedBytesCount = receivedBytesCount;
+
+        // Everything else is 0 for now
+        mProxyStartMs = 0;
+        mProxyEndMs = 0;
+        mDnsStartMs = 0;
+        mDnsEndMs = 0;
+        mConnectStartMs = 0;
+        mConnectEndMs = 0;
+        mSslStartMs = 0;
+        mSslEndMs = 0;
+        mSendingStartMs = 0;
+        mSendingEndMs = 0;
+        mPushStartMs = 0;
+        mPushEndMs = 0;
+        mResponseStartMs = 0;
+        mResponseEndMs = 0;
+        mSocketReused = false;
+    }
+
+    /**
+     * New-style constructor
+     */
+    public CronetMetrics(long proxyStartMs, long proxyEndMs, long dnsStartMs, long dnsEndMs,
+            long connectStartMs, long connectEndMs, long sslStartMs, long sslEndMs,
+            long sendingStartMs, long sendingEndMs, long pushStartMs, long pushEndMs,
+            long responseStartMs, long responseEndMs, boolean socketReused, long sentBytesCount,
+            long receivedBytesCount) {

[xunjieli, 2016/09/01 22:17:42]

Might worth doing some assertions in the constructor to make sure we are passing
the values correctly?

The argument list is pretty long. The arguments are all longs. no pun intended
:) If we switch things around accidentally, we wouldn't know.

How about:
eg. 
assert dnsEnd > dnsStart 
assert connectStartMs > dnsStart 
, etc.?

[mgersh, 2016/09/02 19:32:08]

Yeah, I was worried about that too. Done.

+        mProxyStartMs = proxyStartMs;
+        mProxyEndMs = proxyEndMs;
+        mDnsStartMs = dnsStartMs;
+        mDnsEndMs = dnsEndMs;
+        mConnectStartMs = connectStartMs;
+        mConnectEndMs = connectEndMs;
+        mSslStartMs = sslStartMs;
+        mSslEndMs = sslEndMs;
+        mSendingStartMs = sendingStartMs;
+        mSendingEndMs = sendingEndMs;
+        mPushStartMs = pushStartMs;
+        mPushEndMs = pushEndMs;
+        mResponseStartMs = responseStartMs;
+        mResponseEndMs = responseEndMs;
+        mSocketReused = socketReused;
+        mSentBytesCount = sentBytesCount;
+        mReceivedBytesCount = receivedBytesCount;
+
+        // Don't care about these anymore

[xunjieli, 2016/09/01 22:17:42]

Why do we not care about these anymore? Could you add TODO to get rid of them in
the parent class?

[mgersh, 2016/09/02 19:32:08]

Done.

+        mTtfbMs = null;
+        mTotalTimeMs = null;
+    }
+
+    @Nullable
+    public Date getProxyStart() {
+        return toDate(mProxyStartMs);
+    }
+
+    @Nullable
+    public Date getProxyEnd() {
+        return toDate(mProxyEndMs);
+    }
+
+    @Nullable
+    public Date getDnsStart() {
+        return toDate(mDnsStartMs);
+    }
+
+    @Nullable
+    public Date getDnsEnd() {
+        return toDate(mDnsEndMs);
+    }
+
+    @Nullable
+    public Date getConnectStart() {
+        return toDate(mConnectStartMs);
+    }
+
+    @Nullable
+    public Date getConnectEnd() {
+        return toDate(mConnectEndMs);
+    }
+
+    @Nullable
+    public Date getSslStart() {
+        return toDate(mSslStartMs);
+    }
+
+    @Nullable
+    public Date getSslEnd() {
+        return toDate(mSslEndMs);
+    }
+
+    @Nullable
+    public Date getSendingStart() {
+        return toDate(mSendingStartMs);
+    }
+
+    @Nullable
+    public Date getSendingEnd() {
+        return toDate(mSendingEndMs);
+    }
+
+    @Nullable
+    public Date getPushStart() {
+        return toDate(mPushStartMs);
+    }
+
+    @Nullable
+    public Date getPushEnd() {
+        return toDate(mPushEndMs);
+    }
+
+    @Nullable
+    public Date getResponseStart() {
+        return toDate(mResponseStartMs);
+    }
+
+    @Nullable
+    public Date getResponseEnd() {
+        return toDate(mResponseEndMs);
+    }
+
+    @Nullable
+    public boolean getSocketReused() {
+        return mSocketReused;
+    }
+
+    @Nullable
+    public Long getTtfbMs() {
+        return mTtfbMs;
+    }
+
+    @Nullable
+    public Long getTotalTimeMs() {
+        return mTotalTimeMs;
+    }
+
+    @Nullable
+    public Long getSentBytesCount() {
+        return mSentBytesCount;
+    }
+
+    @Nullable
+    public Long getReceivedBytesCount() {
+        return mReceivedBytesCount;
+    }
+}