Add UMA and Rappor metrics to capture URLs passed in at startup.

chrome/browser/ui/startup/startup_browser_creator_impl.cc

Index: chrome/browser/ui/startup/startup_browser_creator_impl.cc
diff --git a/chrome/browser/ui/startup/startup_browser_creator_impl.cc b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
index 7daf465e1e645f127adc8e255a8a264e69fbc751..7c26d3ce3e3519a96d41f5d24d0acd3bbce99381 100644
--- a/chrome/browser/ui/startup/startup_browser_creator_impl.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
@@ -16,7 +16,7 @@
 #include "base/environment.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
@@ -79,6 +79,7 @@
 #include "chrome/grit/locale_settings.h"
 #include "chrome/installer/util/browser_distribution.h"
 #include "components/google/core/browser/google_util.h"
+#include "components/rappor/rappor_utils.h"
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/dom_storage_context.h"
 #include "content/public/browser/notification_observer.h"
@@ -325,6 +326,10 @@ bool StartupBrowserCreatorImpl::Launch(Profile* profile,
                                        const std::vector<GURL>& urls_to_open,
                                        bool process_startup,
                                        chrome::HostDesktopType desktop_type) {
+  UMA_HISTOGRAM_BOOLEAN("Startup.BrowserLaunchWithURLs",
+                        !urls_to_open.empty());

[Alexei Svitkine (slow), 2015/08/12 18:10:12]

If you're adding this, maybe just record the url count instead of the boolean?

[rkaplow, 2015/08/12 19:54:18]

Done. Probably it's not super necessary but it is strictly more informative so
seems reasonable.

+  RecordRapporOnStartupURLs(urls_to_open);
+
   DCHECK(profile);
   profile_ = profile;
 
@@ -1015,3 +1020,11 @@ void StartupBrowserCreatorImpl::InitializeWelcomeRunType(
     welcome_run_type_ = WelcomeRunType::FIRST_RUN_LAST_TAB;
 #endif  // !OS_WIN
 }
+
+void StartupBrowserCreatorImpl::RecordRapporOnStartupURLs(
+    const std::vector<GURL>& urls_to_open) {
+  for (auto& url : urls_to_open) {

[Alexei Svitkine (slow), 2015/08/12 18:10:12]

Nit: const auto& url or write it out completely - const GURL& url, since it's
short.

[rkaplow, 2015/08/12 19:54:18]

Done.

+    rappor::SampleDomainAndRegistryFromGURL(g_browser_process->rappor_service(),
+                                            "Startup.BrowserLaunchURL", url);
+  }
+}