[WebLayer] Add histograms to measure WebLayer startup

These histograms measure WebLayer startup before WebLayerImpl is loaded,
which we were not measureing before. This will help tell if something
here is contributing to slow startup.

Bug: 1137468
Change-Id: I3e84fc399cf460d60d2e7445326493c528c09178
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2466264
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816590}

components/metrics/generate_expired_histograms_array.gni

@@ -145,6 +145,7 @@ template("generate_expired_histograms_array") {
       "//tools/metrics/histograms/histograms_xml/web_audio/histograms.xml",
       "//tools/metrics/histograms/histograms_xml/web_core/histograms.xml",
       "//tools/metrics/histograms/histograms_xml/web_rtc/histograms.xml",
+      "//tools/metrics/histograms/histograms_xml/weblayer/histograms.xml",
       "//tools/metrics/histograms/histograms_xml/windows/histograms.xml",
       "//tools/metrics/histograms/histograms_xml/obsolete_histograms.xml",
       "//tools/metrics/histograms/enums.xml",

tools/metrics/histograms/histograms_index.txt

@@ -111,4 +111,5 @@ tools/metrics/histograms/histograms_xml/web_apk/histograms.xml
 tools/metrics/histograms/histograms_xml/web_audio/histograms.xml
 tools/metrics/histograms/histograms_xml/web_core/histograms.xml
 tools/metrics/histograms/histograms_xml/web_rtc/histograms.xml
+tools/metrics/histograms/histograms_xml/weblayer/histograms.xml
 tools/metrics/histograms/histograms_xml/windows/histograms.xml
\ No newline at end of file

tools/metrics/histograms/histograms_xml/weblayer/histograms.xml

+<!--
+Copyright 2020 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.
+-->
+
+<!--
+This file is used to generate a comprehensive list of WebLayer histograms
+along with a detailed description for each histogram.
+
+For best practices on writing histogram descriptions, see
+https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md
+
+Please send CLs to chromium-metrics-reviews@google.com rather than to specific
+individuals. These CLs will be automatically reassigned to a reviewer within
+about 5 minutes. This approach helps the metrics team to load-balance incoming
+reviews. Googlers can read more about this at go/gwsq-gerrit.
+-->
+
+<histogram-configuration>
+
+<histograms>
+
+<histogram name="WebLayer.Startup.ClassLoaderCreationTime" units="ms"
+    expires_after="M98">
+  <owner>cduvall@chromium.org</owner>
+  <owner>src/weblayer/OWNERS</owner>
+  <summary>
+    The time it takes for the WebLayer class loader to be created. Recorded at
+    WebLayer startup.
+  </summary>
+</histogram>
+
+<histogram name="WebLayer.Startup.ContextCreationTime" units="ms"
+    expires_after="M98">
+  <owner>cduvall@chromium.org</owner>
+  <owner>src/weblayer/OWNERS</owner>
+  <summary>
+    The time it takes for the WebLayer context to be created. Recorded at
+    WebLayer startup.
+  </summary>
+</histogram>
+
+<histogram name="WebLayer.Startup.WebLayerLoaderCreationTime" units="ms"
+    expires_after="M98">
+  <owner>cduvall@chromium.org</owner>
+  <owner>src/weblayer/OWNERS</owner>
+  <summary>
+    The time it takes for the WebLayer loader to be created. Recorded at
+    WebLayer startup.
+  </summary>
+</histogram>
+
+</histograms>
+
+</histogram-configuration>

weblayer/browser/java/org/chromium/weblayer_private/WebLayerImpl.java

@@ -45,6 +45,7 @@ import org.chromium.base.annotations.NativeMethods;
 import org.chromium.base.compat.ApiHelperForO;
 import org.chromium.base.library_loader.LibraryLoader;
 import org.chromium.base.library_loader.LibraryProcessType;
+import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.components.browser_ui.contacts_picker.ContactsPickerDialog;
 import org.chromium.components.browser_ui.photo_picker.DecoderServiceHost;
 import org.chromium.components.browser_ui.photo_picker.ImageDecoder;
@@ -432,6 +433,19 @@ public final class WebLayerImpl extends IWebLayer.Stub {
     public void setClient(IWebLayerClient client) {
         StrictModeWorkaround.apply();
         sClient = client;
+
+        if (WebLayerFactoryImpl.getClientMajorVersion() >= 88) {
+            try {
+                RecordHistogram.recordTimesHistogram("WebLayer.Startup.ClassLoaderCreationTime",
+                        sClient.getClassLoaderCreationTime());
+                RecordHistogram.recordTimesHistogram(
+                        "WebLayer.Startup.ContextCreationTime", sClient.getContextCreationTime());
+                RecordHistogram.recordTimesHistogram("WebLayer.Startup.WebLayerLoaderCreationTime",
+                        sClient.getWebLayerLoaderCreationTime());
+            } catch (RemoteException e) {
+                throw new APICallException(e);
+            }
+        }
     }
 
     @Override

weblayer/browser/java/org/chromium/weblayer_private/interfaces/IWebLayerClient.aidl

@@ -13,4 +13,9 @@ interface IWebLayerClient {
 
   // Since Version 86.
   Intent createImageDecoderServiceIntent() = 3;
+
+  // Since Version 88.
+  long getClassLoaderCreationTime() = 4;
+  long getContextCreationTime() = 5;
+  long getWebLayerLoaderCreationTime() = 6;
 }

weblayer/public/java/org/chromium/weblayer/WebLayer.java

@@ -14,6 +14,7 @@ import android.os.Bundle;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.StrictMode;
+import android.os.SystemClock;
 import android.util.AndroidRuntimeException;
 import android.util.Log;
 import android.webkit.ValueCallback;
@@ -71,6 +72,11 @@ public class WebLayer {
     @NonNull
     private final IWebLayer mImpl;
 
+    // Times used for logging UMA histograms.
+    private static long sClassLoaderCreationTime;
+    private static long sContextCreationTime;
+    private static long sWebLayerLoaderCreationTime;
+
     /** The result of calling {@link #initializeWebViewCompatibilityMode}. */
     public enum WebViewCompatibilityResult {
         /** Compatibility mode has been successfully set up. */
@@ -274,13 +280,16 @@ public class WebLayer {
                 mContext = mContext.createAttributionContext(context.getAttributionTag());
             }
             try {
-                Class factoryClass = getOrCreateRemoteClassLoader(mContext).loadClass(
-                        "org.chromium.weblayer_private.WebLayerFactoryImpl");
+                ClassLoader classLoader = getOrCreateRemoteClassLoader(mContext);
+                long start = SystemClock.elapsedRealtime();
+                Class factoryClass =
+                        classLoader.loadClass("org.chromium.weblayer_private.WebLayerFactoryImpl");
                 mFactory = IWebLayerFactory.Stub.asInterface(
                         (IBinder) factoryClass
                                 .getMethod("create", String.class, int.class, int.class)
                                 .invoke(null, WebLayerClientVersionConstants.PRODUCT_VERSION,
                                         WebLayerClientVersionConstants.PRODUCT_MAJOR_VERSION, -1));
+                sWebLayerLoaderCreationTime = SystemClock.elapsedRealtime() - start;
                 available = mFactory.isClientSupported();
                 majorVersion = mFactory.getImplementationMajorVersion();
                 version = mFactory.getImplementationVersion();
@@ -598,6 +607,7 @@ public class WebLayer {
             return sRemoteClassLoader;
         }
 
+        long start = SystemClock.elapsedRealtime();
         // Child processes do not need WebView compatibility since there is no chance
         // WebView will run in the same process.
         if (sDisableWebViewCompatibilityMode) {
@@ -617,6 +627,7 @@ public class WebLayer {
         } else {
             sRemoteClassLoader = WebViewCompatibilityHelper.initialize(appContext);
         }
+        sClassLoaderCreationTime = SystemClock.elapsedRealtime() - start;
         return sRemoteClassLoader;
     }
 
@@ -628,6 +639,7 @@ public class WebLayer {
         if (sRemoteContext != null) {
             return sRemoteContext;
         }
+        long start = SystemClock.elapsedRealtime();
         Class<?> webViewFactoryClass = Class.forName("android.webkit.WebViewFactory");
         String implPackageName = getImplPackageName(appContext);
         sAppContext = appContext;
@@ -643,6 +655,7 @@ public class WebLayer {
                     (String) webViewFactoryClass.getMethod("getWebViewPackageName").invoke(null);
             sRemoteContext = createRemoteContextFromPackageName(appContext, implPackageName);
         }
+        sContextCreationTime = SystemClock.elapsedRealtime() - start;
         return sRemoteContext;
     }
 
@@ -721,6 +734,21 @@ public class WebLayer {
             // The id is part of the public library to avoid conflicts.
             return R.id.weblayer_media_session_notification;
         }
+
+        @Override
+        public long getClassLoaderCreationTime() {
+            return sClassLoaderCreationTime;
+        }
+
+        @Override
+        public long getContextCreationTime() {
+            return sContextCreationTime;
+        }
+
+        @Override
+        public long getWebLayerLoaderCreationTime() {
+            return sWebLayerLoaderCreationTime;
+        }
     }
 
     @VerifiesOnO