Download webstore CRXs into separate directory.

chrome/browser/extensions/api/webstore_private/webstore_private_api.cc

Index: chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
diff --git a/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc b/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
index 3c664aae23f8565efe33f515e32e4b7570a4928c..f0bc02173b7d473a53279e38e649c95e2b8c83a3 100644
--- a/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
+++ b/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
@@ -8,6 +8,7 @@
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_vector.h"
+#include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ -183,6 +184,10 @@ void SetWebstoreLogin(Profile* profile, const std::string& login) {
   profile->GetPrefs()->SetString(kWebstoreLogin, login);
 }
 
+void RecordWebstoreExtensionInstallResult(bool success) {
+  UMA_HISTOGRAM_BOOLEAN("Webstore.ExtensionInstallResult", success);

[asargent_no_longer_on_chrome, 2013/11/07 00:18:47]

Does the histograms dashboard have an easy way for you to see the aggregate
values for this broken out by the field trial value? If not you might want to
switch to having two different histogram names, one for each field trial bucket.

[jackhou1, 2013/11/11 22:59:25]

Ah, thanks for pointing this out. The dashboard doesn't, but I think you can
generate histograms prefixed with the field trial using histograms.xml.

+}
+
 }  // namespace
 
 // static
@@ -577,6 +582,8 @@ void WebstorePrivateCompleteInstallFunction::OnExtensionInstallSuccess(
   g_pending_installs.Get().EraseInstall(GetProfile(), id);
   SendResponse(true);
 
+  RecordWebstoreExtensionInstallResult(true);
+
   // Matches the AddRef in RunImpl().
   Release();
 }
@@ -595,6 +602,8 @@ void WebstorePrivateCompleteInstallFunction::OnExtensionInstallFailure(
   g_pending_installs.Get().EraseInstall(GetProfile(), id);
   SendResponse(false);
 
+  RecordWebstoreExtensionInstallResult(false);
+
   // Matches the AddRef in RunImpl().
   Release();
 }