Add UMA metrics to track the source of homescreen icons on launch.

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.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;
 
 import android.app.ActivityManager;
 import android.app.SearchManager;
 import android.content.Context;
 import android.content.Intent;
@@ skipping 594 matching lines @@
                     int tabToBeClobberedIndex = TabModelUtils.getTabIndexByUrl(tabModel, url);
                     Tab tabToBeClobbered = tabModel.getTabAt(tabToBeClobberedIndex);
                     if (tabToBeClobbered != null) {
                         TabModelUtils.setIndex(tabModel, tabToBeClobberedIndex);
                         tabToBeClobbered.reload();
                         RecordUserAction.record("MobileTabClobbered");
                     } else {
                         launchIntent(url, referer, headers, externalAppId, true, intent);
                     }
                     RecordUserAction.record("MobileReceivedExternalIntent");
-                    LaunchMetrics.recordHomeScreenLaunchIntoTab(url);
+                    int shortcutSource = intent.getIntExtra(
+                            ShortcutHelper.EXTRA_SOURCE, ShortcutHelper.SOURCE_UNKNOWN);
+                    LaunchMetrics.recordHomeScreenLaunchIntoTab(url, shortcutSource);
                     break;
                 case REUSE_APP_ID_MATCHING_TAB_ELSE_NEW_TAB:
                     launchIntent(url, referer, headers, externalAppId, false, intent);
                     RecordUserAction.record("MobileReceivedExternalIntent");
                     break;
                 case BRING_TAB_TO_FRONT:
                     mTabModelSelectorImpl.tryToRestoreTabStateForId(tabIdToBringToFront);
 
                     int tabIndex = TabModelUtils.getTabIndexById(tabModel, tabIdToBringToFront);
                     if (tabIndex == TabModel.INVALID_TAB_INDEX) {
@@ skipping 638 matching lines @@
 
     @Override
     public void onOverviewModeFinishedShowing() { }
 
     @Override
     public void onOverviewModeStartedHiding(boolean showToolbar, boolean delayAnimation) {}
 
     @Override
     public void onOverviewModeFinishedHiding() {}
 }