[Cronet] Fix up log TAGs to be accurate and prevent future inaccuracies.

components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java

 // Copyright 2014 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.content.Context;
 import android.os.Build;
 import android.os.ConditionVariable;
 import android.os.Handler;
@@ skipping 25 matching lines @@
 
 /**
  * CronetEngine using Chromium HTTP stack implementation.
  */
 @JNINamespace("cronet")
 @UsedByReflection("CronetEngine.java")
 class CronetUrlRequestContext extends CronetEngine {
     private static final int LOG_NONE = 3;  // LOG(FATAL), no VLOG.
     private static final int LOG_DEBUG = -1;  // LOG(FATAL...INFO), VLOG(1)
     private static final int LOG_VERBOSE = -2;  // LOG(FATAL...INFO), VLOG(2)
-    static final String LOG_TAG = "ChromiumNetwork";

[xunjieli, 2016/07/01 14:11:07]

There was a reason that this TAG is ChromiumNetwork. I am not sure if it is
still applicable. +mef@ to comment.

[mef, 2016/07/01 15:18:18]

I think the reason was mostly historical (based on existing implementation).
I don't mind the rename, but I'm not sure whether class name is the right tag to
use.

2 reasons:
- Wouldn't it be useful to adjust all Cronet logging with one setting as opposed
to X class-specific settings?
- It seems that Chrome likes to prefix tags with 'cr.', should Cronet do the
same?

[pauljensen, 2016/07/01 15:35:22]

I don't feel too strongly as there are pros and cons to both arguments:
1. using the class name is AFAIK the pattern that everyone uses.
2. using the class name makes it easy to track something down, rather than
trying to grep for a particular error message substring
3. using a more general tag like "Cronet" can lead to identical log messages in
different files that are impossible to differentiate
4. using a more general tag like "Cronet" makes it harder to know if you're
adding a log message that is identical to those in another file
5. using a more general tag like "Cronet" helps embedders know it came from
cronet, rather than trying to guess what "CronetUrlRequestContext" is
I don't think this is common in Chrome.  It appears to be less than 10%:
616 instances of "TAG = " in Java files, and only 45 instances of "cr." in
those:
https://cs.chromium.org/search/?q=%22TAG+%3D+%22+file:java&sq=package:chromiu...
https://cs.chromium.org/search/?q=%22TAG+%3D+%22+file:java+%22cr.%22&sq=packa...

[mef, 2016/07/13 19:15:58]

Acknowledged. I don't feel strongly either, and following common pattern sgtm.
Missing "cr_" is added by org.chromium.base.Log:
https://cs.chromium.org/chromium/src/base/android/java/src/org/chromium/base/...

I think we should drop explicit "cr." from our code, and use
org.chromium.base.Log in implementation. WDYT?

[pauljensen, 2016/08/17 11:58:33]

Done.

+    static final String LOG_TAG = CronetUrlRequestContext.class.getSimpleName();
 
     /**
      * Synchronize access to mUrlRequestContextAdapter and shutdown routine.
      */
     private final Object mLock = new Object();
     private final ConditionVariable mInitCompleted = new ConditionVariable(false);
     private final AtomicInteger mActiveRequestCount = new AtomicInteger(0);
 
     private long mUrlRequestContextAdapter = 0;
     private Thread mNetworkThread;
@@ skipping 518 matching lines @@
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeEnableNetworkQualityEstimator(long nativePtr);
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeProvideRTTObservations(long nativePtr, boolean should);
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeProvideThroughputObservations(long nativePtr, boolean should);
 }