drive: Stop returning scoped_ptr from ResourceMetadataStorage::GetHeader

BUG=None
TEST=unit_tests
R=kinaba@chromium.org

Review URL: https://codereview.chromium.org/17210003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207349 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 16 insertions, 24 deletions

diff --git a/chrome/browser/chromeos/drive/resource_metadata_storage.cc b/chrome/browser/chromeos/drive/resource_metadata_storage.cc
index d596dc6..b9c8bbf 100644
--- a/chrome/browser/chromeos/drive/resource_metadata_storage.cc
+++ b/chrome/browser/chromeos/drive/resource_metadata_storage.cc
@@ -230,8 +230,8 @@ bool ResourceMetadataStorage::Initialize() {
     resource_map_.reset(db);
 
     // Check the validity of existing DB.
-    scoped_ptr<ResourceMetadataHeader> header = GetHeader();
-    if (!header || header->version() != kDBVersion) {
+    ResourceMetadataHeader header;
+    if (!GetHeader(&header) || header.version() != kDBVersion) {
       open_existing_result = DB_INIT_INCOMPATIBLE;
       LOG(INFO) << "Reject incompatible DB.";
     } else if (!CheckValidity()) {
@@ -288,23 +288,23 @@ bool ResourceMetadataStorage::SetLargestChangestamp(
     int64 largest_changestamp) {
   base::ThreadRestrictions::AssertIOAllowed();
 
-  scoped_ptr<ResourceMetadataHeader> header = GetHeader();
-  if (!header) {
+  ResourceMetadataHeader header;
+  if (!GetHeader(&header)) {
     DLOG(ERROR) << "Failed to get the header.";
     return false;
   }
-  header->set_largest_changestamp(largest_changestamp);
-  return PutHeader(*header);
+  header.set_largest_changestamp(largest_changestamp);
+  return PutHeader(header);
 }
 
 int64 ResourceMetadataStorage::GetLargestChangestamp() {
   base::ThreadRestrictions::AssertIOAllowed();
-  scoped_ptr<ResourceMetadataHeader> header = GetHeader();
-  if (!header) {
+  ResourceMetadataHeader header;
+  if (!GetHeader(&header)) {
     DLOG(ERROR) << "Failed to get the header.";
     return 0;
   }
-  return header->largest_changestamp();
+  return header.largest_changestamp();
 }
 
 bool ResourceMetadataStorage::PutEntry(const ResourceEntry& entry) {
@@ -492,8 +492,7 @@ bool ResourceMetadataStorage::PutHeader(
   return status.ok();
 }
 
-scoped_ptr<ResourceMetadataHeader>
-ResourceMetadataStorage::GetHeader() {
+bool ResourceMetadataStorage::GetHeader(ResourceMetadataHeader* header) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   std::string serialized_header;
@@ -501,14 +500,7 @@ ResourceMetadataStorage::GetHeader() {
       leveldb::ReadOptions(),
       leveldb::Slice(GetHeaderDBKey()),
       &serialized_header);
-  if (!status.ok())
-    return scoped_ptr<ResourceMetadataHeader>();
-
-  scoped_ptr<ResourceMetadataHeader> header(
-      new ResourceMetadataHeader);
-  if (!header->ParseFromString(serialized_header))
-    return scoped_ptr<ResourceMetadataHeader>();
-  return header.Pass();
+  return status.ok() && header->ParseFromString(serialized_header);
 }
 
 bool ResourceMetadataStorage::CheckValidity() {
diff --git a/chrome/browser/chromeos/drive/resource_metadata_storage.h b/chrome/browser/chromeos/drive/resource_metadata_storage.h
index edd4a3f..c4d12f1 100644
--- a/chrome/browser/chromeos/drive/resource_metadata_storage.h
+++ b/chrome/browser/chromeos/drive/resource_metadata_storage.h
@@ -147,7 +147,7 @@ class ResourceMetadataStorage {
   bool PutHeader(const ResourceMetadataHeader& header);
 
   // Gets header.
-  scoped_ptr<ResourceMetadataHeader> GetHeader();
+  bool GetHeader(ResourceMetadataHeader* out_header);
 
   // Checks validity of the data.
   bool CheckValidity();
diff --git a/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc b/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
index 14e711b..ae57e65 100644
--- a/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
+++ b/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
@@ -28,10 +28,10 @@ class ResourceMetadataStorageTest : public testing::Test {
 
   // Overwrites |storage_|'s version.
   void SetDBVersion(int version) {
-    scoped_ptr<ResourceMetadataHeader> header = storage_->GetHeader();
-    ASSERT_TRUE(header);
-    header->set_version(version);
-    storage_->PutHeader(*header);
+    ResourceMetadataHeader header;
+    ASSERT_TRUE(storage_->GetHeader(&header));
+    header.set_version(version);
+    EXPECT_TRUE(storage_->PutHeader(header));
   }
 
   bool CheckValidity() {