[android_webview] Do not extract webviewchromium.pak

android_webview/browser/aw_browser_main_parts.cc

Index: android_webview/browser/aw_browser_main_parts.cc
diff --git a/android_webview/browser/aw_browser_main_parts.cc b/android_webview/browser/aw_browser_main_parts.cc
index 29e9003755682f2aa04e2e21031bf2aace38b876..2abc6c2ccac6c907c87d87acc024a5c9c1cd031f 100644
--- a/android_webview/browser/aw_browser_main_parts.cc
+++ b/android_webview/browser/aw_browser_main_parts.cc
@@ -6,6 +6,7 @@
 
 #include "android_webview/browser/aw_browser_context.h"
 #include "android_webview/browser/aw_result_codes.h"
+#include "android_webview/native/aw_assets.h"
 #include "base/android/build_info.h"
 #include "base/android/memory_pressure_listener_android.h"
 #include "base/command_line.h"
@@ -19,6 +20,7 @@
 #include "gpu/command_buffer/service/mailbox_synchronizer.h"
 #include "net/android/network_change_notifier_factory_android.h"
 #include "net/base/network_change_notifier.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_android.h"
 #include "ui/base/layout.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -45,15 +47,57 @@ void AwBrowserMainParts::PreEarlyInitialization() {
 }
 
 int AwBrowserMainParts::PreCreateThreads() {
-  ui::ResourceBundle::InitSharedInstanceLocaleOnly(
-      l10n_util::GetDefaultLocale(), NULL);
-
-  base::FilePath pak_path;
-  PathService::Get(ui::DIR_RESOURCE_PAKS_ANDROID, &pak_path);
+  int pak_fd = 0;
+  int64 pak_off = 0;
+  int64 pak_len = 0;
+
+  // TODO(primiano): at present state there is a cyclic logic dependency
+  // between l10n_util::GetApplicationLocale and our code here. l10n_util
+  // decides which locale to ultimately use by scanning the pak files in the
+  // data folder. What we ultimately want to achieve is knowing the pak file to
+  // load from the apk beforehand, without looking at the data folder at all.
+  // Fixing this cyclic dependency involves some refactoring in ResourceBundle
+  // and l10n_util.
+  // In the meanwhile we use the mmap path only as a fallback (i.e. we check
+  // first for the existence of the pak files in the data dir). In the immediate
+  // future this order should be reversed, and we should look in the data
+  // directory only if we failed to mmap the pak file from the apk.
+  bool did_init_from_file = !ui::ResourceBundle::InitSharedInstanceLocaleOnly(
+                                 l10n_util::GetDefaultLocale(), NULL).empty();
+  if (!did_init_from_file) {
+    LOG(WARNING) << "Failed to load the locale pak from PATH_SERVICE. "
+                    " Trying to mmap en-US.pak from the apk";
+    if (AwAssets::OpenAsset("en-US.pak", &pak_fd, &pak_off, &pak_len)) {
+      VLOG(0) << "Load from apk succesful, fd=" << pak_fd << " off=" << pak_off
+              << " len=" << pak_len;
+      ui::ResourceBundle::CleanupSharedInstance();
+      ui::ResourceBundle::InitSharedInstanceWithPakFileRegion(
+          base::File(pak_fd),
+          base::MemoryMappedFile::Region(pak_off, pak_len),
+          /*should_load_common_resources=*/false);
+    } else {
+      LOG(WARNING) << "Failed to load en-US.pak from the apk too. "
+                      "Bringing up WebView without any locale";
+    }
+  }
 
-  ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
-      pak_path.AppendASCII("webviewchromium.pak"),
-      ui::SCALE_FACTOR_NONE);
+  // Try to directly mmap the webviewchromium.pak from the apk. Fall back to
+  // load from file, using PATH_SERVICE, otherwise.
+  if (AwAssets::OpenAsset("webviewchromium.pak", &pak_fd, &pak_off, &pak_len)) {
+    VLOG(0) << "Loading webviewchromium.pak from, fd:" << pak_fd
+            << " off:" << pak_off << " len:" << pak_len;
+    ui::ResourceBundle::GetSharedInstance().AddDataPackFromFileRegion(
+        base::File(pak_fd),
+        base::MemoryMappedFile::Region(pak_off, pak_len),
+        ui::SCALE_FACTOR_NONE);
+  } else {
+    base::FilePath pak_path;
+    PathService::Get(ui::DIR_RESOURCE_PAKS_ANDROID, &pak_path);
+    LOG(WARNING) << "Cannot load webviewchromium.pak assets from the apk. "
+                    "Falling back loading it from " << pak_path.MaybeAsASCII();
+    ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
+        pak_path.AppendASCII("webviewchromium.pak"), ui::SCALE_FACTOR_NONE);
+  }
 
   base::android::MemoryPressureListenerAndroid::RegisterSystemCallback(
       base::android::AttachCurrentThread());