Randomize order in which ready component updates are applied. On demand...

Randomize order in which ready component updates are applied. On demand updates still take precedence.

BUG=343686

Review URL: https://codereview.chromium.org/144523004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255832 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/component_updater/component_updater_service.cc

@@ -16,6 +16,7 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/rand_util.h"
 #include "base/sequenced_task_runner.h"
 #include "base/stl_util.h"
 #include "base/threading/sequenced_worker_pool.h"
@@ -574,23 +575,26 @@ void CrxUpdateService::ProcessPendingItems() {
 }
 
 CrxUpdateItem* CrxUpdateService::FindReadyComponent() const {
-  class Helper {
-   public:
-    static bool IsReadyOnDemand(CrxUpdateItem* item) {
-      return item->on_demand && IsReady(item);
-    }
-    static bool IsReady(CrxUpdateItem* item) {
-      return item->status == CrxUpdateItem::kCanUpdate;
+  std::vector<CrxUpdateItem*> ready;
+  std::vector<CrxUpdateItem*> ready_on_demand;
+  for (std::vector<CrxUpdateItem*>::const_iterator it = work_items_.begin();
+       it != work_items_.end();
+       ++it) {
+    CrxUpdateItem* item = *it;
+    if (item->status == CrxUpdateItem::kCanUpdate) {
+      if (item->on_demand)
+        ready_on_demand.push_back(item);
+      else
+        ready.push_back(item);
     }
-  };
+  }
 
-  std::vector<CrxUpdateItem*>::const_iterator it = std::find_if(
-      work_items_.begin(), work_items_.end(), Helper::IsReadyOnDemand);
-  if (it != work_items_.end())
-    return *it;
-  it = std::find_if(work_items_.begin(), work_items_.end(), Helper::IsReady);
-  if (it != work_items_.end())
-    return *it;
+  if (ready_on_demand.size() > 0) {
+    return ready_on_demand[base::RandInt(0, ready_on_demand.size() - 1)];
+  }
+  if (ready.size() > 0) {
+    return ready[base::RandInt(0, ready.size() - 1)];
+  }
   return NULL;
 }