Add instrumentation to the Android resource extraction.

The instrumentation uses android.os.Trace instead of the more common
org.chromium.base.TraceEvent as the resource extraction is typically
done before the native library initialization, so TraceEvent calls are
dropped (per TraceEvent documentation).

BUG=445718

Review URL: https://codereview.chromium.org/805693003

Cr-Commit-Position: refs/heads/master@{#310772}

base/android/java/src/org/chromium/base/ResourceExtractor.java

@@ -10,6 +10,7 @@ import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.AssetManager;
 import android.os.AsyncTask;
+import android.os.Trace;
 import android.preference.PreferenceManager;
 import android.util.Log;
 
@@ -52,15 +53,20 @@ public class ResourceExtractor {
         public ExtractTask() {
         }
 
-        @Override
-        protected Void doInBackground(Void... unused) {
+        private void doInBackgroundImpl() {
             final File outputDir = getOutputDir();
             if (!outputDir.exists() && !outputDir.mkdirs()) {
                 Log.e(LOGTAG, "Unable to create pak resources directory!");
-                return null;
+                return;
             }
 
-            String timestampFile = checkPakTimestamp(outputDir);
+            String timestampFile = null;
+            Trace.beginSection("checkPakTimeStamp");
+            try {
+                timestampFile = checkPakTimestamp(outputDir);
+            } finally {
+                Trace.endSection();
+            }
             if (timestampFile != null) {
                 deleteFiles();
             }
@@ -72,7 +78,7 @@ public class ResourceExtractor {
             String currentLanguage = currentLocale.split("-", 2)[0];
 
             if (prefs.getString(LAST_LANGUAGE, "").equals(currentLanguage)
-                    &&  filenames.size() >= sMandatoryPaks.length) {
+                    && filenames.size() >= sMandatoryPaks.length) {
                 boolean filesPresent = true;
                 for (String file : filenames) {
                     if (!new File(outputDir, file).exists()) {
@@ -80,7 +86,7 @@ public class ResourceExtractor {
                         break;
                     }
                 }
-                if (filesPresent) return null;
+                if (filesPresent) return;
             } else {
                 prefs.edit().putString(LAST_LANGUAGE, currentLanguage).apply();
             }
@@ -93,9 +99,9 @@ public class ResourceExtractor {
 
             if (sExtractImplicitLocalePak) {
                 if (p.length() > 0) p.append('|');
-                // As well as the minimum required set of .paks above, we'll also add all .paks that
-                // we have for the user's currently selected language.
-
+                // As well as the minimum required set of .paks above, we'll
+                // also add all .paks that we have for the user's currently
+                // selected language.
                 p.append(currentLanguage);
                 p.append("(-\\w+)?\\.pak");
             }
@@ -103,6 +109,7 @@ public class ResourceExtractor {
             Pattern paksToInstall = Pattern.compile(p.toString());
 
             AssetManager manager = mContext.getResources().getAssets();
+            Trace.beginSection("WalkAssets");
             try {
                 // Loop through every asset file that we have in the APK, and look for the
                 // ones that we need to extract by trying to match the Patterns that we
@@ -114,16 +121,16 @@ public class ResourceExtractor {
                         continue;
                     }
                     boolean isAppDataFile = file.equals(ICU_DATA_FILENAME)
-                                      || file.equals(V8_NATIVES_DATA_FILENAME)
-                                      || file.equals(V8_SNAPSHOT_DATA_FILENAME);
-                    File output = new File(isAppDataFile
-                                           ? getAppDataDir() : outputDir, file);
+                            || file.equals(V8_NATIVES_DATA_FILENAME)
+                            || file.equals(V8_SNAPSHOT_DATA_FILENAME);
+                    File output = new File(isAppDataFile ? getAppDataDir() : outputDir, file);
                     if (output.exists()) {
                         continue;
                     }
 
                     InputStream is = null;
                     OutputStream os = null;
+                    Trace.beginSection("ExtractResource");
                     try {
                         is = manager.open(file);
                         os = new FileOutputStream(output);
@@ -159,6 +166,7 @@ public class ResourceExtractor {
                             if (os != null) {
                                 os.close();
                             }
+                            Trace.endSection(); // ExtractResource
                         }
                     }
                 }
@@ -169,11 +177,12 @@ public class ResourceExtractor {
                 // this happens with regularity.
                 Log.w(LOGTAG, "Exception unpacking required pak resources: " + e.getMessage());
                 deleteFiles();
-                return null;
+                return;
+            } finally {
+                Trace.endSection(); // WalkAssets
             }
 
             // Finished, write out a timestamp file if we need to.
-
             if (timestampFile != null) {
                 try {
                     new File(outputDir, timestampFile).createNewFile();
@@ -186,6 +195,20 @@ public class ResourceExtractor {
             // TODO(yusufo): Figure out why remove is required here.
             prefs.edit().remove(PAK_FILENAMES).apply();
             prefs.edit().putStringSet(PAK_FILENAMES, filenames).apply();
+        }
+
+        @Override
+        protected Void doInBackground(Void... unused) {
+            // TODO(lizeb): Use chrome tracing here (and above in
+            // doInBackgroundImpl) when it will be possible. This is currently
+            // not doable since the native library is not loaded yet, and the
+            // TraceEvent calls are dropped before this point.
+            Trace.beginSection("ResourceExtractor.ExtractTask.doInBackground");
+            try {
+                doInBackgroundImpl();
+            } finally {
+                Trace.endSection();
+            }
             return null;
         }