Implement coarse "on demand" functionality for update checks.

chrome/browser/component_updater/component_updater_service.cc

Index: chrome/browser/component_updater/component_updater_service.cc
diff --git a/chrome/browser/component_updater/component_updater_service.cc b/chrome/browser/component_updater/component_updater_service.cc
index 367ff6e7d5ec326a0ca0d6807f36c76b4e5d3cd2..6b0d7f766105353beb7013bae162c0df6e6d30f6 100644
--- a/chrome/browser/component_updater/component_updater_service.cc
+++ b/chrome/browser/component_updater/component_updater_service.cc
@@ -63,11 +63,15 @@ const CrxComponent::UrlSource kManifestSources[] = {
 bool AddQueryString(const std::string& id,
                     const std::string& version,
                     const std::string& fingerprint,
+                    bool ondemand,
                     size_t limit,
                     std::string* query) {
   std::string additional =
-      base::StringPrintf("id=%s&v=%s&fp=%s&uc",
-                         id.c_str(), version.c_str(), fingerprint.c_str());
+      base::StringPrintf("id=%s&v=%s&fp=%s&uc%s",
+                         id.c_str(),
+                         version.c_str(),
+                         fingerprint.c_str(),
+                         ondemand ? "&installsource=ondemand" : "");
   additional = "x=" + net::EscapeQueryParamValue(additional, true);
   if ((additional.size() + query->size() + 1) > limit)
     return false;
@@ -381,7 +385,9 @@ class CrxUpdateService : public ComponentUpdateService {
   // See ManifestParserBridge.
   void OnParseUpdateManifestFailed(const std::string& error_message);
 
-  bool AddItemToUpdateCheck(CrxUpdateItem* item, std::string* query);
+  bool AddItemToUpdateCheck(CrxUpdateItem* item,
+                            bool ondemand,
+                            std::string* query);
 
   void ProcessPendingItems();
 
@@ -571,11 +577,14 @@ ComponentUpdateService::Status CrxUpdateService::RegisterComponent(
 // required omaha compatible query. Returns false when the query strings
 // is longer than specified by UrlSizeLimit().
 bool CrxUpdateService::AddItemToUpdateCheck(CrxUpdateItem* item,
+                                            bool ondemand,
                                             std::string* query) {
   if (!AddQueryString(item->id,
                       item->component.version.GetString(),
                       item->component.fingerprint,
-                      config_->UrlSizeLimit(), query))
+                      ondemand,
+                      config_->UrlSizeLimit(),
+                      query))
     return false;
 
   item->status = CrxUpdateItem::kChecking;
@@ -590,6 +599,9 @@ bool CrxUpdateService::AddItemToUpdateCheck(CrxUpdateItem* item,
 
 // Start the process of checking for an update, for a particular component
 // that was previously registered.
+// If the component is still at version "0" (representing not-yet-installed),
+// the update check will be an "on-demand" updatecheck, which the server may
+// choose to handle differently.
 ComponentUpdateService::Status CrxUpdateService::CheckForUpdateSoon(
     const CrxComponent& component) {
   if (component.pk_hash.empty() ||
@@ -690,7 +702,9 @@ void CrxUpdateService::ProcessPendingItems() {
         continue;
       if (item->component.source != manifest_source)
         continue;
-      if (!AddItemToUpdateCheck(item, &query))
+      bool ondemand = requested_work_items_.count(item) &&
+          item->component.version.Equals(Version("0"));

[cpu_(ooo_6.6-7.5), 2013/06/21 00:22:56]

I don't think so. This is hacky and the on-demand is not just at v0 but in all
cases where the current component is incompatible with the action that the user
needs to do.

How about we check if the item is on the requested_work_items_ and set the flag
if so?

[waffles, 2013/06/21 01:52:08]

Done.

I had the Version==0 check in response to mevissen@'s concerns about components
calling CheckForUpdateSoon too aggressively and triggering constant "on demand"
updatechecks that aren't on demand. Indeed, PNaCl calls CheckForUpdateSoon every
browser boot.

Closer inspection shows that there is a CL in the CQ that changes that, and
additionally only calls CheckForUpdateSoon if the version == 0; so I've removed
the version check here.

+      if (!AddItemToUpdateCheck(item, ondemand, &query))
         break;
       // Requested work items may speed up the update cycle up until
       // the point that we start an update check. I.e., transition
@@ -717,7 +731,7 @@ void CrxUpdateService::ProcessPendingItems() {
       base::TimeDelta delta = base::Time::Now() - item->last_check;
       if (delta < min_delta_time)
         continue;
-      if (!AddItemToUpdateCheck(item, &query))
+      if (!AddItemToUpdateCheck(item, false, &query))
         break;
     }
 
@@ -733,7 +747,7 @@ void CrxUpdateService::ProcessPendingItems() {
       base::TimeDelta delta = base::Time::Now() - item->last_check;
       if (delta < min_delta_time)
         continue;
-      if (!AddItemToUpdateCheck(item, &query))
+      if (!AddItemToUpdateCheck(item, false, &query))
         break;
     }