Add UMA metrics regarding default browser status

chrome/android/java/src/org/chromium/chrome/browser/DefaultBrowserInfo.java

Index: chrome/android/java/src/org/chromium/chrome/browser/DefaultBrowserInfo.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/DefaultBrowserInfo.java b/chrome/android/java/src/org/chromium/chrome/browser/DefaultBrowserInfo.java
index 5477da8e5d919194e7702f6de8d1c44b736d213d..30b0045bf77775ac8f965dbe652c6f079a3bfd9e 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/DefaultBrowserInfo.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/DefaultBrowserInfo.java
@@ -6,30 +6,77 @@ package org.chromium.chrome.browser;
 
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.net.Uri;
 import android.os.AsyncTask;
+import android.support.annotation.IntDef;
+import android.text.TextUtils;
 
 import org.chromium.base.BuildInfo;
 import org.chromium.base.ContextUtils;
+import org.chromium.base.library_loader.LibraryProcessType;
+import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+import org.chromium.content.browser.BrowserStartupController;
 
 import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.RejectedExecutionException;
 
 /**
  * A utility class for querying information about the default browser setting.
  */
-public class DefaultBrowserInfo {
+public final class DefaultBrowserInfo {
     private static final String SAMPLE_URL = "https://www.madeupdomainforcheck123.com/";
 
+    /**
+     * A list of potential default browser states.  Please keep this in sync with
+     * MobileDefaultBrowserState in histograms.xml.
+     */
+    @IntDef({
+            MobileDefaultBrowserState.NO_DEFAULT,
+            MobileDefaultBrowserState.CHROME_SYSTEM_DEFAULT,
+            MobileDefaultBrowserState.CHROME_INSTALLED_DEFAULT,
+            MobileDefaultBrowserState.OTHER_SYSTEM_DEFAULT,
+            MobileDefaultBrowserState.OTHER_INSTALLED_DEFAULT,
+
+            MobileDefaultBrowserState.BOUNDARY,
+    })
+    private @interface MobileDefaultBrowserState {
+    int NO_DEFAULT = 0;

[nyquist, 2017/04/27 05:20:06]

clang-format!! y u no make sense!?

+    int CHROME_SYSTEM_DEFAULT = 1;
+    int CHROME_INSTALLED_DEFAULT = 2;
+    int OTHER_SYSTEM_DEFAULT = 3;
+    int OTHER_INSTALLED_DEFAULT = 4;
+    int BOUNDARY = 5;
+    }
+
+    /**
+     * Helper class for passing information about the system's default browser settings back from a
+     * worker task.
+     */
+    private static class DefaultInfo {
+        public boolean isChromeDefault;
+        public boolean isChromeSystem;
+        public boolean isDefaultSystem;
+        public boolean hasDefault;
+        public int browserCount;
+    }
+
     /** A lock to synchronize background tasks to retrieve browser information. */
     private static final Object sDirCreationLock = new Object();
 
     private static AsyncTask<Void, Void, ArrayList<String>> sDefaultBrowserFetcher;
 
+    /** Don't instantiate me. */
+    private DefaultBrowserInfo() {}
+
     /**
      * Initialize an AsyncTask for getting menu title of opening a link in default browser.
      */
@@ -102,4 +149,90 @@ public class DefaultBrowserInfo {
                     R.string.menu_open_in_product_default);
         }
     }
+
+    /**
+     * Log statistics about the current default browser to UMA.
+     */
+    public static void logDefaultBrowserStats() {
+        assert BrowserStartupController.get(LibraryProcessType.PROCESS_BROWSER)
+                .isStartupSuccessfullyCompleted();
+
+        try {
+            new AsyncTask<Context, Void, DefaultInfo>() {
+                @Override
+                protected DefaultInfo doInBackground(Context... params) {
+                    Context context = params[0];
+
+                    PackageManager pm = context.getPackageManager();
+
+                    Intent intent = new Intent(Intent.ACTION_VIEW);
+                    intent.setData(Uri.parse(SAMPLE_URL));
+
+                    DefaultInfo info = new DefaultInfo();
+
+                    // Query the default handler first.
+                    ResolveInfo defaultRi = pm.resolveActivity(intent, 0);
+                    if (defaultRi != null && defaultRi.match != 0) {
+                        info.hasDefault = true;
+                        info.isChromeDefault = isSamePackage(context, defaultRi);
+                        info.isDefaultSystem = isSystemPackage(defaultRi);
+                    }
+
+                    // Query all other intent handlers.
+                    Set<String> uniquePackages = new HashSet<>();
+                    List<ResolveInfo> ris =
+                            pm.queryIntentActivities(intent, PackageManager.MATCH_ALL);
+                    for (ResolveInfo ri : ris) {
+                        if (isSamePackage(context, ri)) info.isChromeSystem = isSystemPackage(ri);

[nyquist, 2017/04/27 05:20:06]

Optional nit: Is isChromeSystem really necessary?
Or could we use info.isDefaultSystem on line 222 below instead? We seem to only
check isChromeSystem if Chrome is already the default browser.

That being said though, I really don't feel strongly about this, and I think the
current version is also very easy to read below, but you can remove this line if
you remove the isChromeSystem member, making this loop incredibly short and to
the point.

[David Trainor- moved to gerrit, 2017/04/28 01:03:18]

Fair point!

+                        uniquePackages.add(ri.activityInfo.applicationInfo.packageName);
+                    }
+
+                    info.browserCount = uniquePackages.size();
+
+                    return info;
+                }
+
+                @Override
+                protected void onPostExecute(DefaultInfo info) {
+                    if (info == null) return;
+
+                    RecordHistogram.recordCount100Histogram(
+                            getDefaultBrowserCountUmaName(info), info.browserCount);
+                    RecordHistogram.recordEnumeratedHistogram("Mobile.DefaultBrowser.State",
+                            getDefaultBrowserUmaState(info), MobileDefaultBrowserState.BOUNDARY);
+                }
+            }
+                    .executeOnExecutor(
+                            AsyncTask.THREAD_POOL_EXECUTOR, ContextUtils.getApplicationContext());
+        } catch (RejectedExecutionException ex) {
+            // Fail silently here since this is not a critical task.
+        }
+    }
+
+    private static String getDefaultBrowserCountUmaName(DefaultInfo info) {
+        if (!info.hasDefault) return "Mobile.DefaultBrowser.BrowserCount.NoDefault";
+        if (info.isChromeDefault) return "Mobile.DefaultBrowser.BrowserCount.ChromeDefault";
+        return "Mobile.DefaultBrowser.BrowserCount.OtherDefault";
+    }
+
+    private static @MobileDefaultBrowserState int getDefaultBrowserUmaState(DefaultInfo info) {
+        if (!info.hasDefault) return MobileDefaultBrowserState.NO_DEFAULT;
+
+        if (info.isChromeDefault) {
+            if (info.isChromeSystem) return MobileDefaultBrowserState.CHROME_SYSTEM_DEFAULT;
+            return MobileDefaultBrowserState.CHROME_INSTALLED_DEFAULT;
+        }
+
+        if (info.isDefaultSystem) return MobileDefaultBrowserState.OTHER_SYSTEM_DEFAULT;
+        return MobileDefaultBrowserState.OTHER_INSTALLED_DEFAULT;
+    }
+
+    private static boolean isSamePackage(Context context, ResolveInfo info) {
+        return TextUtils.equals(
+                context.getPackageName(), info.activityInfo.applicationInfo.packageName);
+    }
+
+    private static boolean isSystemPackage(ResolveInfo info) {
+        return (info.activityInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
+    }
 }