Add a histogram for tracking web store promo

chrome/browser/dom_ui/new_tab_ui.cc

Index: chrome/browser/dom_ui/new_tab_ui.cc
diff --git a/chrome/browser/dom_ui/new_tab_ui.cc b/chrome/browser/dom_ui/new_tab_ui.cc
index a6621026a946daaeab375912be7b9a32f3450b7f..14b84e3e90e2a2d2f28246c9e93db2613fd43d52 100644
--- a/chrome/browser/dom_ui/new_tab_ui.cc
+++ b/chrome/browser/dom_ui/new_tab_ui.cc
@@ -15,6 +15,7 @@
 #include "base/metrics/histogram.h"
 #include "base/singleton.h"
 #include "base/string_number_conversions.h"
+#include "base/string_split.h"
 #include "base/thread.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser.h"
@@ -40,6 +41,7 @@
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
@@ -620,7 +622,16 @@ void NewTabUI::NewTabHTMLSource::StartDataRequest(const std::string& path,
                                                   int request_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  if (!path.empty() && path[0] != '#') {
+  if (path.find(extension_misc::kLaunchWebStorePingURL) != std::string::npos) {

[Aaron Boodman, 2010/11/12 00:29:20]

Can you isolate all of this in AppLauncherHandler instead? The code sort of
makes more sense there than here. That way the constants can also be in
app_launcher_handler.* instead of in extension_constants.*.

You could have like static bool AppLauncherHandler::HandlePing(path). If it
returns true then it was handled, otherwise, this code goes on to do what it
usually does.

The RecordXYZ() methods would become private statics of AppLauncherHandler.

+    RecordWebStoreLaunch(IsPromoActive(path));
+    return;
+
+  } else if (path.find(extension_misc::kLaunchAppPingURL) !=
+             std::string::npos) {
+    RecordAppLaunch(IsPromoActive(path));
+    return;
+
+  } else if (!path.empty() && path[0] != '#') {
     // A path under new-tab was requested; it's likely a bad relative
     // URL from the new tab page, but in any case it's an error.
     NOTREACHED();
@@ -636,3 +647,31 @@ void NewTabUI::NewTabHTMLSource::StartDataRequest(const std::string& path,
 std::string NewTabUI::NewTabHTMLSource::GetMimeType(const std::string&) const {
   return "text/html";
 }
+
+void NewTabUI::NewTabHTMLSource::RecordWebStoreLaunch(bool promo_active) {
+  if (!promo_active) return;
+
+  UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppsPromoHistogram,
+                            extension_misc::PROMO_LAUNCH_WEB_STORE,
+                            extension_misc::PROMO_BUCKET_BOUNDARY);
+}
+
+void NewTabUI::NewTabHTMLSource::RecordAppLaunch(bool promo_active) {
+  // TODO(jstritar): record app launches that occur when the promo is not
+  // active using a different histogram.
+
+  if (!promo_active) return;
+
+  UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppsPromoHistogram,
+                            extension_misc::PROMO_LAUNCH_APP,
+                            extension_misc::PROMO_BUCKET_BOUNDARY);
+}
+
+bool NewTabUI::NewTabHTMLSource::IsPromoActive(const std::string& path) {
+  std::vector<std::string> params;
+  base::SplitString(path, '+', &params);
+
+  DCHECK(params.size() == 2);

[Aaron Boodman, 2010/11/12 00:29:20]

You are going to crash below if size < 2, so might as well CHECK here. It's a
programmer error that this would ever not be 2.

+
+  return params.at(1) == "true";
+}