tools: Local tests for the speculative prefetch predictor.

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

 // 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.customtabs;
 
 import android.app.ActivityManager;
 import android.app.Application;
 import android.app.PendingIntent;
 import android.content.Context;
@@ skipping 15 matching lines @@
 import android.support.customtabs.CustomTabsSessionToken;
 import android.text.TextUtils;
 import android.util.Pair;
 import android.widget.RemoteViews;
 
 import org.chromium.base.CommandLine;
 import org.chromium.base.Log;
 import org.chromium.base.SysUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.TimeUtils;
+import org.chromium.base.TraceEvent;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.base.library_loader.ProcessInitException;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeApplication;
 import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.IntentHandler;
 import org.chromium.chrome.browser.WarmupManager;
 import org.chromium.chrome.browser.device.DeviceClassManager;
@@ skipping 192 matching lines @@
      */
     private boolean warmupInternal(final boolean mayCreateSpareWebContents) {
         // Here and in mayLaunchUrl(), don't do expensive work for background applications.
         if (!isCallerForegroundOrSelf()) return false;
         mClientManager.recordUidHasCalledWarmup(Binder.getCallingUid());
         final boolean initialized = !mWarmupHasBeenCalled.compareAndSet(false, true);
         final int uid = Binder.getCallingUid();
         // The call is non-blocking and this must execute on the UI thread, post a task.
         ThreadUtils.postOnUiThread(new Runnable() {
             @Override
             public void run() {

[pasko, 2016/11/21 17:33:02]

this easier to read at least to me:

try {
  TraceEvent.begin("CustomTabsConnection.warmupInternal()");
  runInternal();
} finally {
  TraceEvent.end("CustomTabsConnection.warmupInternal()");
}

but up to you

-                if (!initialized) initializeBrowser(mApplication);
-                if (mayCreateSpareWebContents && mSpeculation == null
-                        && !SysUtils.isLowEndDevice()) {
-                    WarmupManager.getInstance().createSpareWebContents();
-                    // The throttling database uses shared preferences, that can cause a StrictMode
-                    // violation on the first access. Make sure that this access is not in
-                    // mayLauchUrl.
-                    RequestThrottler.getForUid(mApplication, uid);
+                TraceEvent.begin("CustomTabsConnection.warmupInternal()");
+                try {
+                    if (!initialized) initializeBrowser(mApplication);
+                    if (mayCreateSpareWebContents && mSpeculation == null
+                            && !SysUtils.isLowEndDevice()) {
+                        WarmupManager.getInstance().createSpareWebContents();
+                    }
+                    if (!initialized) {
+                        // The throttling database uses shared preferences, that can cause a
+                        // StrictMode violation on the first access. Make sure that this access is
+                        // not in mayLauchUrl.
+                        RequestThrottler.getForUid(mApplication, uid);
 
-                    Profile profile = Profile.getLastUsedProfile();
-                    new ResourcePrefetchPredictor(profile).startInitialization();
+                        Profile profile = Profile.getLastUsedProfile();
+                        new ResourcePrefetchPredictor(profile).startInitialization();
+                    }
+                    mWarmupHasBeenFinished.set(true);
+                } finally {
+                    TraceEvent.end("CustomTabsConnection.warmupInternal()");
                 }
-                mWarmupHasBeenFinished.set(true);
             }
         });
         return true;
     }
 
     /** @return the URL converted to string, or null if it's invalid. */
     private static String checkAndConvertUri(Uri uri) {
         if (uri == null) return null;
         // Don't do anything for unknown schemes. Not having a scheme is allowed, as we allow
         // "www.example.com".
@@ skipping 68 matching lines @@
             if (url != null) {
                 warmupManager.maybePreconnectUrlAndSubResources(profile, url);
                 atLeastOneUrl = true;
             }
         }
         return atLeastOneUrl;
     }
 
     public boolean mayLaunchUrl(CustomTabsSessionToken session, Uri url, Bundle extras,
             List<Bundle> otherLikelyBundles) {
-        boolean success = mayLaunchUrlInternal(session, url, extras, otherLikelyBundles);
-        logCall("mayLaunchUrl()", success);
-        return success;
+        TraceEvent.begin("CustomTabsConnection.mayLaunchUrl()");
+        try {
+            boolean success = mayLaunchUrlInternal(session, url, extras, otherLikelyBundles);
+            logCall("mayLaunchUrl()", success);
+            return success;
+        } finally {
+            TraceEvent.end("CustomTabsConnection.mayLaunchUrl()");
+        }
     }
 
     private boolean mayLaunchUrlInternal(final CustomTabsSessionToken session, Uri url,
             final Bundle extras, final List<Bundle> otherLikelyBundles) {
         final boolean lowConfidence =
                 (url == null || TextUtils.isEmpty(url.toString())) && otherLikelyBundles != null;
         final String urlString = checkAndConvertUri(url);
         if (url != null && urlString == null && !lowConfidence) return false;
 
         // Things below need the browser process to be initialized.
 
         // Forbids warmup() from creating a spare renderer, as prerendering wouldn't reuse
         // it. Checking whether prerendering is enabled requires the native library to be loaded,
         // which is not necessarily the case yet.
         if (!warmupInternal(false)) return false; // Also does the foreground check.
 
         final int uid = Binder.getCallingUid();
         // TODO(lizeb): Also throttle low-confidence mode.
         if (!lowConfidence
                 && !mClientManager.updateStatsAndReturnWhetherAllowed(session, uid, urlString)) {
             return false;
         }
         ThreadUtils.postOnUiThread(new Runnable() {
             @Override
             public void run() {
-                if (lowConfidence) {
-                    lowConfidenceMayLaunchUrl(otherLikelyBundles);
-                } else {
-                    highConfidenceMayLaunchUrl(session, uid, urlString, extras, otherLikelyBundles);
+                TraceEvent.begin("CustomTabsConnection.mayLaunchUrlInternal()");
+                try {
+                    if (lowConfidence) {
+                        lowConfidenceMayLaunchUrl(otherLikelyBundles);
+                    } else {
+                        highConfidenceMayLaunchUrl(
+                                session, uid, urlString, extras, otherLikelyBundles);
+                    }
+                } finally {
+                    TraceEvent.end("CustomTabsConnection.mayLaunchUrlInternal()");
                 }
             }
         });
         return true;
     }
 
     public Bundle extraCommand(String commandName, Bundle args) {
         return null;
     }
 
@@ skipping 525 matching lines @@
     @VisibleForTesting
     void resetThrottling(Context context, int uid) {
         mClientManager.resetThrottling(uid);
     }
 
     @VisibleForTesting
     void ban(Context context, int uid) {
         mClientManager.ban(uid);
     }
 }