Log a rappor metric for external app ids.

BUG=640734

Review-Url: https://codereview.chromium.org/2272863004
Cr-Commit-Position: refs/heads/master@{#414318}

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

@@ -307,6 +307,12 @@ public class IntentHandler {
         ExternalAppId externalId = determineExternalIntentSource(mPackageName, intent);
         RecordHistogram.recordEnumeratedHistogram("MobileIntent.PageLoadDueToExternalApp",
                 externalId.ordinal(), ExternalAppId.INDEX_BOUNDARY.ordinal());
+        if (externalId == ExternalAppId.OTHER) {
+            String appId = IntentUtils.safeGetStringExtra(intent, Browser.EXTRA_APPLICATION_ID);
+            if (!TextUtils.isEmpty(appId)) {
+                RapporServiceBridge.sampleString("Android.PageLoadDueToExternalApp", appId);
+            }
+        }
     }
 
     /**

tools/metrics/rappor/rappor.xml

@@ -146,6 +146,15 @@ components/rappor/rappor_parameters.h.
   </summary>
 </rappor-metric>
 
+<rappor-metric name="Android.PageLoadDueToExternalApp" type="UMA_RAPPOR_TYPE">
+  <owner>mariakhomenko@chromium.org</owner>
+  <summary>
+    The package name of an application that sent an intent to Chrome. The name
+    is taken from EXTRA_APPLICATION_ID passed to Chrome in the intent by the
+    application.
+  </summary>
+</rappor-metric>
+
 <rappor-metric name="AppBanner.NativeApp.Dismissed" type="ETLD_PLUS_ONE">
   <owner>dfalcantara@chromium.org</owner>
   <summary>