Use base::Time for modification time instead of a plain int64_t

Also, update the comment about the 'modification_time' field in the
compression request.

BUG=889703

Change-Id: I37df9e8abc50b195b73ffd9cf101444dc682ff33
Reviewed-on: https://chromium-review.googlesource.com/c/1279199
Commit-Queue: Anand Mistry <amistry@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599735}

chrome/browser/resources/chromeos/zip_archiver/cpp/compressor.cc

@@ -10,6 +10,7 @@
 #include <string>
 #include <utility>
 
+#include "base/time/time.h"
 #include "chrome/browser/resources/chromeos/zip_archiver/cpp/compressor_archive_minizip.h"
 #include "chrome/browser/resources/chromeos/zip_archiver/cpp/compressor_io_javascript_stream.h"
 #include "chrome/browser/resources/chromeos/zip_archiver/cpp/javascript_compressor_requestor_interface.h"
@@ -93,8 +94,9 @@ void Compressor::AddToArchiveCallback(int32_t,
   bool is_directory = dictionary.Get(request::key::kIsDirectory).AsBool();
 
   PP_DCHECK(dictionary.Get(request::key::kModificationTime).is_string());
-  // Since modification_time is milliseconds, we hold the value in int64_t.
-  int64_t modification_time = static_cast<int64_t>(
+  // modification_time comes from a JS Date object, which expresses time in
+  // milliseconds since the UNIX epoch.
+  base::Time modification_time = base::Time::FromJsTime(
       request::GetInt64FromString(dictionary, request::key::kModificationTime));
 
   if (!compressor_archive_->AddToArchive(pathname, file_size, modification_time,

chrome/browser/resources/chromeos/zip_archiver/cpp/compressor_archive.h

@@ -8,6 +8,8 @@
 #include <cstdint>
 #include <string>
 
+#include "base/time/time.h"
+
 class CompressorStream;
 
 // Defines a wrapper for packing operations executed on an archive. API is not
@@ -45,7 +47,7 @@ class CompressorArchive {
   // can be obtained with CompressorArchive::error_message().
   virtual bool AddToArchive(const std::string& filename,
                             int64_t file_size,
-                            int64_t modification_time,
+                            base::Time modification_time,
                             bool is_directory) = 0;
 
   // A getter function for compressor_stream_.

chrome/browser/resources/chromeos/zip_archiver/cpp/compressor_archive_minizip.cc

@@ -23,13 +23,13 @@ const char kCloseArchiveError[] = "Failed to close archive.";
 // We need at least 256KB for MiniZip.
 const int64_t kMaximumDataChunkSize = 512 * 1024;
 
-uint32_t UnixToDosdate(const int64_t datetime) {
-  tm tm_datetime;
-  localtime_r(&datetime, &tm_datetime);
+uint32_t UnixToDosdate(const base::Time datetime) {
+  base::Time::Exploded exploded;
+  datetime.LocalExplode(&exploded);
 
-  return (tm_datetime.tm_year - 80) << 25 | (tm_datetime.tm_mon + 1) << 21 |
-         tm_datetime.tm_mday << 16 | tm_datetime.tm_hour << 11 |
-         tm_datetime.tm_min << 5 | (tm_datetime.tm_sec >> 1);
+  return (exploded.year - 1980) << 25 | exploded.month << 21 |
+         exploded.day_of_month << 16 | exploded.hour << 11 |
+         exploded.minute << 5 | exploded.second >> 1;
 }
 
 };  // namespace
@@ -160,7 +160,7 @@ bool CompressorArchiveMinizip::CreateArchive() {
 
 bool CompressorArchiveMinizip::AddToArchive(const std::string& filename,
                                             int64_t file_size,
-                                            int64_t modification_time,
+                                            base::Time modification_time,
                                             bool is_directory) {
   // Minizip takes filenames that end with '/' as directories.
   std::string normalized_filename = filename;
@@ -169,8 +169,7 @@ bool CompressorArchiveMinizip::AddToArchive(const std::string& filename,
 
   // Fill zipfileMetadata with modification_time.
   zip_fileinfo zipfileMetadata;
-  // modification_time is millisecond-based, while FromTimeT takes seconds.
-  zipfileMetadata.dos_date = UnixToDosdate((int64_t)modification_time / 1000);
+  zipfileMetadata.dos_date = UnixToDosdate(modification_time);
 
   // Section 4.4.4 http://www.pkware.com/documents/casestudies/APPNOTE.TXT
   // Setting the Language encoding flag so the file is told to be in utf-8.

chrome/browser/resources/chromeos/zip_archiver/cpp/compressor_archive_minizip.h

@@ -49,7 +49,7 @@ class CompressorArchiveMinizip : public CompressorArchive {
   // Adds an entry to the archive.
   bool AddToArchive(const std::string& filename,
                     int64_t file_size,
-                    int64_t modification_time,
+                    base::Time modification_time,
                     bool is_directory) override;
 
   // A getter function for zip_file_.

chrome/browser/resources/chromeos/zip_archiver/cpp/request.h

@@ -46,8 +46,8 @@ const char kEntryId[] = "entry_id";                    // Should be an int.
 const char kPathname[] = "pathname";                   // Should be a string.
 const char kFileSize[] = "file_size";                  // Should be a string.
 const char kIsDirectory[] = "is_directory";            // Should be a bool.
-const char kModificationTime[] = "modification_time";  // Should be a string
-                                                       // (mm/dd/yy h:m:s).
+// Local time in milliseconds since UNIX epoch, as a string.
+const char kModificationTime[] = "modification_time";
 const char kHasError[] = "has_error";                  // Should be a bool.
 
 // Optional keys used for both packing and unpacking operations.

chrome/browser/resources/chromeos/zip_archiver/js/request.js

@@ -41,15 +41,15 @@ unpacker.request = {
     COMPRESSOR_ID: 'compressor_id',  // Should be an int.
 
     // Optional keys unique to packing operations.
-    ENTRY_ID: 'entry_id',                    // Should be an int.
-    PATHNAME: 'pathname',                    // should be a string.
-    FILE_SIZE: 'file_size',                  // should be a string. Same reason
-                                             // as ARCHIVE_SIZE.
-    IS_DIRECTORY: 'is_directory',            // should be a boolean.
-    MODIFICATION_TIME: 'modification_time',  // should be a string.
-                                             // (mm/dd/yy h:m:s)
-    HAS_ERROR: 'has_error',                  // Should be a boolean Sent from JS
-                                             // to NaCL.
+    ENTRY_ID: 'entry_id',          // Should be an int.
+    PATHNAME: 'pathname',          // should be a string.
+    FILE_SIZE: 'file_size',        // should be a string. Same reason
+                                   // as ARCHIVE_SIZE.
+    IS_DIRECTORY: 'is_directory',  // should be a boolean.
+    // Local time in milliseconds since UNIX epoch, as a string.
+    MODIFICATION_TIME: 'modification_time',
+    HAS_ERROR: 'has_error',  // Should be a boolean Sent from JS
+                             // to NaCL.
 
     // Optional keys used for both packing and unpacking operations.
     ERROR: 'error',                // Should be a string.