Load language .pak files directly from the apk when using splits

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index d5a8247355a9cca09d6396b0aad3c6a52bd06a2e..8b31175b67946ac182cdcdc6707a2c1ed2adedcb 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -157,6 +157,8 @@
 #elif defined(OS_LINUX)
 #include "chrome/browser/chrome_browser_main_linux.h"
 #elif defined(OS_ANDROID)
+#include "base/android/apk_assets.h"
+#include "base/android/build_info.h"
 #include "chrome/browser/android/new_tab_page_url_handler.h"
 #include "chrome/browser/android/webapps/single_tab_mode_tab_helper.h"
 #include "chrome/browser/chrome_browser_main_android.h"
@@ -2224,18 +2226,30 @@ void ChromeContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
       &(*regions)[kAndroidChrome100PercentPakDescriptor]);
   mappings->Share(kAndroidChrome100PercentPakDescriptor, fd);
 
-  int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-  const std::string locale = GetApplicationLocale();
-  base::FilePath locale_pak = ResourceBundle::GetSharedInstance().
-      GetLocaleFilePath(locale, false);
-  base::File file(locale_pak, flags);
-  DCHECK(file.IsValid());
-  mappings->Transfer(kAndroidLocalePakDescriptor,
-                     base::ScopedFD(file.TakePlatformFile()));
+  if (!locale_pak_fd_.is_valid()) {
+    const std::string locale = GetApplicationLocale();
+    if (ui::GetLocalePaksStoredInApk()) {
+      std::string pak_path = ui::GetPathForAndroidLocalePakWithinApk(locale);
+      locale_pak_fd_.reset(
+          base::android::OpenApkAsset(pak_path, &locale_pak_region_));
+    } else {
+      int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
+      base::FilePath locale_pak = ResourceBundle::GetSharedInstance().
+          GetLocaleFilePath(locale, false);
+      base::File file(locale_pak, flags);
+      locale_pak_fd_.reset(file.TakePlatformFile());
+      locale_pak_region_ = base::MemoryMappedFile::Region::kWholeFile;
+    }
+    DCHECK(locale_pak_fd_.is_valid());
+  }
+  mappings->Share(kAndroidLocalePakDescriptor, locale_pak_fd_.get());
+  regions->insert(
+      std::make_pair(kAndroidLocalePakDescriptor, locale_pak_region_));
 
   if (breakpad::IsCrashReporterEnabled()) {
-    file = breakpad::CrashDumpManager::GetInstance()->CreateMinidumpFile(
-               child_process_id);
+    base::File file =
+          breakpad::CrashDumpManager::GetInstance()->CreateMinidumpFile(
+              child_process_id);
     if (file.IsValid()) {
       mappings->Transfer(kAndroidMinidumpDescriptor,
                          base::ScopedFD(file.TakePlatformFile()));