Prevent duplicate concurrent installs of the same extension

chrome/browser/extensions/webstore_standalone_installer.cc

Index: chrome/browser/extensions/webstore_standalone_installer.cc
diff --git a/chrome/browser/extensions/webstore_standalone_installer.cc b/chrome/browser/extensions/webstore_standalone_installer.cc
index 4f42f01b221312bc01654531b520157d9c2244e0..9eba52f7de5edc7d77bd167f484c1d32f26e7066 100644
--- a/chrome/browser/extensions/webstore_standalone_installer.cc
+++ b/chrome/browser/extensions/webstore_standalone_installer.cc
@@ -10,6 +10,7 @@
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/extensions/extension_install_ui.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/install_tracker.h"
 #include "chrome/browser/extensions/webstore_data_fetcher.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/web_contents.h"
@@ -31,6 +32,8 @@ const char kInvalidWebstoreResponseError[] = "Invalid Chrome Web Store reponse";
 const char kInvalidManifestError[] = "Invalid manifest";
 const char kUserCancelledError[] = "User cancelled install";
 const char kExtensionIsBlacklisted[] = "Extension is blacklisted";
+const char kInstallInProgressError[] = "An install is already in progress";
+const char kLaunchInProgressError[] = "A launch is already in progress";
 
 WebstoreStandaloneInstaller::WebstoreStandaloneInstaller(
     const std::string& webstore_item_id,
@@ -56,6 +59,13 @@ void WebstoreStandaloneInstaller::BeginInstall() {
     return;
   }
 
+  webstore_install::Result result = webstore_install::UNKNOWN_ERROR;
+  std::string error;
+  if (!EnsureUniqueInstall(&result, &error)) {
+    CompleteInstall(result, error);
+    return;
+  }
+
   // Use the requesting page as the referrer both since that is more correct
   // (it is the page that caused this request to happen) and so that we can
   // track top sites that trigger inline install requests.
@@ -79,13 +89,40 @@ void WebstoreStandaloneInstaller::AbortInstall() {
   // Abort any in-progress fetches.
   if (webstore_data_fetcher_) {
     webstore_data_fetcher_.reset();
+    scoped_active_install_.reset();
     Release();  // Matches the AddRef in BeginInstall.
   }
 }
 
+bool WebstoreStandaloneInstaller::EnsureUniqueInstall(
+    webstore_install::Result* reason,
+    std::string* error) {
+  InstallTracker* tracker = InstallTracker::Get(profile_);
+  DCHECK(tracker);
+
+  const ActiveInstallData* existing_install_data =
+      tracker->GetActiveInstall(id_);
+  if (existing_install_data) {
+    if (existing_install_data->is_ephemeral) {
+      *reason = webstore_install::LAUNCH_IN_PROGRESS;
+      *error = kLaunchInProgressError;
+    } else {
+      *reason = webstore_install::INSTALL_IN_PROGRESS;
+      *error = kInstallInProgressError;
+    }
+    return false;
+  }
+
+  ActiveInstallData install_data(id_);
+  InitInstallData(&install_data);
+  scoped_active_install_.reset(new ScopedActiveInstall(tracker, install_data));
+  return true;
+}
+
 void WebstoreStandaloneInstaller::CompleteInstall(
     webstore_install::Result result,
     const std::string& error) {
+  scoped_active_install_.reset();
   if (!callback_.is_null())
     callback_.Run(result == webstore_install::SUCCESS, error);
   Release();  // Matches the AddRef in BeginInstall.
@@ -121,6 +158,11 @@ WebstoreStandaloneInstaller::GetLocalizedExtensionForDisplay() {
   return localized_extension_for_display_.get();
 }
 
+void WebstoreStandaloneInstaller::InitInstallData(
+    ActiveInstallData* install_data) const {
+  // Default implementation sets no properties.
+}
+
 void WebstoreStandaloneInstaller::OnManifestParsed() {
   ProceedWithInstallPrompt();
 }