Revert of Revert of Drive: Let DriveUploader use batch request API.

chrome/browser/chromeos/drive/job_queue.cc

Index: chrome/browser/chromeos/drive/job_queue.cc
diff --git a/chrome/browser/chromeos/drive/job_queue.cc b/chrome/browser/chromeos/drive/job_queue.cc
index e1ea3174020f53f526ee12a43f6af13ffd9610eb..f6070b1dc91a83259bd32af164e91a76ff0f1d87 100644
--- a/chrome/browser/chromeos/drive/job_queue.cc
+++ b/chrome/browser/chromeos/drive/job_queue.cc
@@ -41,22 +41,18 @@
     return;
 
   // Looks up the queue in the order of priority upto |accepted_priority|.
-  bool processing_batch_request = false;
-  int64 total_size = 0;
+  uint64 total_size = 0;
+  bool batchable = true;
   for (int priority = 0; priority <= accepted_priority; ++priority) {
-    auto it = queue_[priority].begin();
-    while (it != queue_[priority].end()) {
-      if (!processing_batch_request ||
-          (it->batchable && total_size + it->size <= max_batch_size_)) {
-        total_size += it->size;
-        processing_batch_request = it->batchable;
-        jobs->push_back(it->id);
-        running_.insert(it->id);
-        it = queue_[priority].erase(it);
-        if (processing_batch_request)
-          continue;
-      }
-      return;
+    while (!queue_[priority].empty()) {
+      const auto& item = queue_[priority].front();
+      total_size += item.size;
+      batchable = batchable && item.batchable && total_size <= max_batch_size_;
+      if (!(jobs->empty() || batchable))
+        return;
+      jobs->push_back(item.id);
+      running_.insert(item.id);
+      queue_[priority].pop_front();
     }
   }
 }