Add an API to component_updater that asks to do an update check "now".

chrome/browser/component_updater/pnacl/pnacl_component_installer.cc

Index: chrome/browser/component_updater/pnacl/pnacl_component_installer.cc
diff --git a/chrome/browser/component_updater/pnacl/pnacl_component_installer.cc b/chrome/browser/component_updater/pnacl/pnacl_component_installer.cc
index fbbb315e3af7d9f426408043d2987ed6081ba219..03597fc309765077b86df372eb6688d250153e43 100644
--- a/chrome/browser/component_updater/pnacl/pnacl_component_installer.cc
+++ b/chrome/browser/component_updater/pnacl/pnacl_component_installer.cc
@@ -25,6 +25,11 @@ using content::BrowserThread;
 
 namespace {
 
+// If PNaCl isn't installed yet, but a user is running chrome with
+// --enable-pnacl, this is the amount of time to wait before starting
+// a background install.
+const int kInitialDelaySeconds = 10;
+
 // One of the Pnacl component files, for checking that expected files exist.
 // TODO(jvoung): perhaps replace this with a list of the expected files in the
 // manifest.json. Use that to check that everything is unpacked.
@@ -127,10 +132,6 @@ void SetPnaclHash(CrxComponent* component) {
 
 
 // If we don't have Pnacl installed, this is the version we claim.
-// TODO(jvoung): Is there a way to trick the configurator to ping the server
-// earlier if there are components that are not yet installed (version 0.0.0.0),
-// So that they will be available ASAP? Be careful not to hurt startup speed.
-// Make kNullVersion part of ComponentUpdater in that case, to avoid skew?
 const char kNullVersion[] = "0.0.0.0";
 
 // Pnacl components have the version encoded in the path itself:
@@ -314,6 +315,13 @@ bool PnaclComponentInstaller::Install(base::DictionaryValue* manifest,
 
 namespace {
 
+void DoCheckForUpdate(ComponentUpdateService* cus,
+                   const CrxComponent& pnacl) {
+  if (cus->CheckForUpdateSoon(pnacl) != ComponentUpdateService::kOk) {
+    LOG(WARNING) << "Pnacl check for update failed.";
+  }
+}
+
 // Finally, do the registration with the right version number.
 void FinishPnaclUpdateRegistration(ComponentUpdateService* cus,
                                    const Version& current_version) {
@@ -328,6 +336,16 @@ void FinishPnaclUpdateRegistration(ComponentUpdateService* cus,
   if (cus->RegisterComponent(pnacl) != ComponentUpdateService::kOk) {
     NOTREACHED() << "Pnacl component registration failed.";
   }
+
+  // If Pnacl is not yet installed, but it is requested by --enable-pnacl,
+  // we want it to be available "soon", so kick off an update check.
+  Version null_version(kNullVersion);
+  if (current_version.Equals(null_version)) {
+    BrowserThread::PostDelayedTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(DoCheckForUpdate, cus, pnacl),
+        base::TimeDelta::FromSeconds(kInitialDelaySeconds));
+  }
 }
 
 // Check if there is an existing version on disk first to know when