Fix FakeDriveService's behavior to be more correct.

chrome/browser/google_apis/fake_drive_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/google_apis/fake_drive_service.h"
 
 #include <string>
 
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 792 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
 
   if (offline_) {
     MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, GDATA_NO_CONNECTION, GURL()));
     return;
   }
 
-  DictionaryValue* entry = FindEntryByResourceId(parent_resource_id);
-  if (!entry) {
+  if (parent_resource_id != GetRootResourceId() &&
+      !FindEntryByResourceId(parent_resource_id)) {
     MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, HTTP_NOT_FOUND, GURL()));
     return;
   }
 
   // If the title was set, the upload_location is the location of the parent
   // directory of the file that will be uploaded. The file does not yet exist
   // and it must be created. Its title will be the passed title param.
   std::string resource_id = GetNewResourceId();
@@ skipping 86 matching lines @@
   DictionaryValue* entry = FindEntryByResourceId(resource_id);
   if (!entry) {
     MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, HTTP_NOT_FOUND, GURL()));
     return;
   }
 
   std::string entry_etag;
   entry->GetString("gd$etag", &entry_etag);
-  if (etag != entry_etag) {
+  if (!etag.empty() && etag != entry_etag) {
     MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, HTTP_PRECONDITION, GURL()));
     return;
   }
 
   std::string upload_url;
   base::ListValue* links = NULL;
   if (entry->GetList("link", &links) && links) {
     for (size_t link_index = 0;
@@ skipping 189 matching lines @@
   return base::StringPrintf("resource_id_%d", resource_id_count_);
 }
 
 void FakeDriveService::AddNewChangestamp(base::DictionaryValue* entry) {
   ++largest_changestamp_;
   entry->SetString("docs$changestamp.value",
                    base::Int64ToString(largest_changestamp_));
 }
 
 }  // namespace google_apis