Add chrome.webstore API methods to allow sites to see progress of installation

chrome/browser/extensions/install_tracker.cc

Index: chrome/browser/extensions/install_tracker.cc
diff --git a/chrome/browser/extensions/install_tracker.cc b/chrome/browser/extensions/install_tracker.cc
index 67503028f3561150b21a94a4e51b5b5a663d04af..e7014f693100eff87a6da88f55f88c7efae556e1 100644
--- a/chrome/browser/extensions/install_tracker.cc
+++ b/chrome/browser/extensions/install_tracker.cc
@@ -53,12 +53,22 @@ void InstallTracker::OnBeginExtensionInstall(
                     OnBeginExtensionInstall(params));
 }
 
+void InstallTracker::OnBeginExtensionDownload(const std::string& extension_id) {
+  FOR_EACH_OBSERVER(
+      InstallObserver, observers_, OnBeginExtensionDownload(extension_id));
+}
+
 void InstallTracker::OnDownloadProgress(const std::string& extension_id,
                                         int percent_downloaded) {
   FOR_EACH_OBSERVER(InstallObserver, observers_,
                     OnDownloadProgress(extension_id, percent_downloaded));
 }
 
+void InstallTracker::OnBeginCrxInstall(const std::string& extension_id) {
+  FOR_EACH_OBSERVER(
+      InstallObserver, observers_, OnBeginCrxInstall(extension_id));
+}
+
 void InstallTracker::OnInstallFailure(
     const std::string& extension_id) {
   FOR_EACH_OBSERVER(InstallObserver, observers_,