Reland http://codereview.chromium.org/4139008, with a different

chrome/browser/extensions/convert_web_app.cc

+// Copyright (c) 2010 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/extensions/convert_web_app.h"
+
+#include <cmath>
+#include <limits>
+#include <string>
+#include <vector>
+
+#include "base/base64.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/path_service.h"
+#include "base/scoped_temp_dir.h"
+#include "base/sha2.h"
+#include "base/stringprintf.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/extension_constants.h"
+#include "chrome/common/json_value_serializer.h"
+#include "gfx/codec/png_codec.h"
+#include "googleurl/src/gurl.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "webkit/glue/dom_operations.h"
+
+namespace keys = extension_manifest_keys;
+
+using base::Time;
+
+namespace {
+
+const char kIconsDirName[] = "_icons";
+
+// Create the public key for the converted web app.
+//
+// Web apps are not signed, but the public key for an extension doubles as
+// its unique identity, and we need one of those. A web app's unique identity
+// is its manifest URL, so we hash that to create a public key. There will be
+// no corresponding private key, which means that these extensions cannot be
+// auto-updated using ExtensionUpdater. But Chrome does notice updates to the
+// manifest and regenerates these extensions.
+std::string GenerateKey(const GURL& manifest_url) {
+  char raw[base::SHA256_LENGTH] = {0};
+  std::string key;
+  base::SHA256HashString(manifest_url.spec().c_str(),
+                         raw,
+                         base::SHA256_LENGTH);
+  base::Base64Encode(std::string(raw, base::SHA256_LENGTH), &key);
+  return key;
+}
+
+}
+
+
+// Generates a version for the converted app using the current date. This isn't
+// really needed, but it seems like useful information.
+std::string ConvertTimeToExtensionVersion(const Time& create_time) {
+  Time::Exploded create_time_exploded;
+  create_time.UTCExplode(&create_time_exploded);
+
+  double micros =
+      (create_time_exploded.millisecond * Time::kMicrosecondsPerMillisecond) +
+      (create_time_exploded.second * Time::kMicrosecondsPerSecond) +
+      (create_time_exploded.minute * Time::kMicrosecondsPerMinute) +
+      (create_time_exploded.hour * Time::kMicrosecondsPerHour);
+  LOG(ERROR) << "micros: " << micros;
+  double day_fraction = micros / Time::kMicrosecondsPerDay;
+  LOG(ERROR) << "day_fraction: " << day_fraction;
+  double stamp = round(day_fraction * std::numeric_limits<uint16>::max());
+  LOG(ERROR) << "stamp: " << stamp;
+
+  return base::StringPrintf("%i.%i.%i.%i",
+                            create_time_exploded.year,
+                            create_time_exploded.month,
+                            create_time_exploded.day_of_month,
+                            static_cast<uint16>(stamp));
+}
+
+scoped_refptr<Extension> ConvertWebAppToExtension(
+    const webkit_glue::WebApplicationInfo& web_app,
+    const Time& create_time) {
+  FilePath user_data_temp_dir;
+  CHECK(PathService::Get(chrome::DIR_USER_DATA_TEMP, &user_data_temp_dir));
+
+  ScopedTempDir temp_dir;
+  if (!temp_dir.CreateUniqueTempDirUnderPath(user_data_temp_dir)) {
+    LOG(ERROR) << "Could not create temporary directory.";
+    return NULL;
+  }
+
+  // Create the manifest
+  scoped_ptr<DictionaryValue> root(new DictionaryValue);
+  root->SetString(keys::kPublicKey, GenerateKey(web_app.manifest_url));
+  root->SetString(keys::kName, UTF16ToUTF8(web_app.title));
+  root->SetString(keys::kVersion, ConvertTimeToExtensionVersion(create_time));
+  root->SetString(keys::kDescription, UTF16ToUTF8(web_app.description));
+  root->SetString(keys::kLaunchWebURL, web_app.app_url.spec());
+
+  // Add the icons.
+  DictionaryValue* icons = new DictionaryValue();
+  root->Set(keys::kIcons, icons);
+  for (size_t i = 0; i < web_app.icons.size(); ++i) {
+    std::string size = StringPrintf("%i", web_app.icons[i].width);
+    std::string icon_path = StringPrintf("%s/%s.png", kIconsDirName,
+                                         size.c_str());
+    icons->SetString(size, icon_path);
+  }
+
+  // Add the permissions.
+  ListValue* permissions = new ListValue();
+  root->Set(keys::kPermissions, permissions);
+  for (size_t i = 0; i < web_app.permissions.size(); ++i) {
+    permissions->Append(Value::CreateStringValue(web_app.permissions[i]));
+  }
+
+  // Add the URLs.
+  ListValue* urls = new ListValue();
+  root->Set(keys::kWebURLs, urls);
+  for (size_t i = 0; i < web_app.urls.size(); ++i) {
+    urls->Append(Value::CreateStringValue(web_app.urls[i].spec()));
+  }
+
+  // Write the manifest.
+  FilePath manifest_path = temp_dir.path().Append(
+      Extension::kManifestFilename);
+  JSONFileValueSerializer serializer(manifest_path);
+  if (!serializer.Serialize(*root)) {
+    LOG(ERROR) << "Could not serialize manifest.";
+    return NULL;
+  }
+
+  // Write the icon files.
+  FilePath icons_dir = temp_dir.path().AppendASCII(kIconsDirName);
+  if (!file_util::CreateDirectory(icons_dir)) {
+    LOG(ERROR) << "Could not create icons directory.";
+    return NULL;
+  }
+  for (size_t i = 0; i < web_app.icons.size(); ++i) {
+    FilePath icon_file = icons_dir.AppendASCII(
+        StringPrintf("%i.png", web_app.icons[i].width));
+    std::vector<unsigned char> image_data;
+    if (!gfx::PNGCodec::EncodeBGRASkBitmap(web_app.icons[i].data,
+                                           false,
+                                           &image_data)) {
+      LOG(ERROR) << "Could not create icon file.";
+      return NULL;
+    }
+
+    const char* image_data_ptr = reinterpret_cast<const char*>(&image_data[0]);
+    if (!file_util::WriteFile(icon_file, image_data_ptr, image_data.size())) {
+      LOG(ERROR) << "Could not write icon file.";
+      return NULL;
+    }
+  }
+
+  // Finally, create the extension object to represent the unpacked directory.
+  std::string error;
+  scoped_refptr<Extension> extension = Extension::Create(
+      temp_dir.path(), Extension::INTERNAL, *root, false, &error);
+  if (!extension) {
+    LOG(ERROR) << error;
+    return NULL;
+  }
+
+  temp_dir.Take();  // The caller takes ownership of the directory.
+  return extension;
+}