Store and load icudtl.dat directly from the apk rather than extracting on start-up

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 e07ea7aa1525c34b4ffab0b1a833072daa79498a..20c1c340eb17a96ad9aa5341ffa5c2b6c605bd7e 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -174,6 +174,7 @@
 #endif
 
 #if defined(OS_ANDROID)
+#include "base/android/apk_assets.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/gfx/android/device_display_info.h"
 #endif
@@ -2223,7 +2224,12 @@ void ChromeContentBrowserClient::GetAdditionalFileSystemBackends(
 void ChromeContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     const base::CommandLine& command_line,
     int child_process_id,
-    FileDescriptorInfo* mappings) {
+    FileDescriptorInfo* mappings
+#if defined(OS_ANDROID)
+    ,
+    std::map<int, base::MemoryMappedFile::Region>* regions
+#endif
+    ) {
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
   if (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
     int v8_natives_fd = -1;
@@ -2279,17 +2285,14 @@ void ChromeContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     }
   }
 
-  base::FilePath app_data_path;
-  PathService::Get(base::DIR_ANDROID_APP_DATA, &app_data_path);
-  DCHECK(!app_data_path.empty());
-
-  flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-  base::FilePath icudata_path =
-      app_data_path.AppendASCII(base::i18n::kIcuDataFileName);
-  base::File icudata_file(icudata_path, flags);
-  DCHECK(icudata_file.IsValid());
-  mappings->Transfer(kAndroidICUDataDescriptor,
-                     base::ScopedFD(icudata_file.TakePlatformFile()));
+  if (!icudtl_fd_.is_valid()) {
+    icudtl_fd_.reset(base::android::OpenApkAsset(base::i18n::kIcuDataFileName,
+          &icudtl_region_));
+    DCHECK(icudtl_fd_.is_valid());
+  }
+  mappings->Share(kAndroidICUDataDescriptor, icudtl_fd_.get());
+  regions->insert(std::make_pair(kAndroidICUDataDescriptor, icudtl_region_));

[jam, 2015/06/04 03:13:30]

why is chrome layer doing this instead of content layer? content knows about ICU

[agrieve, 2015/06/04 19:17:20]

I'm new to this code, and have no idea. I do know content still is the one to
use the FD that's opened here. Maybe the authors wanted to keep all
renderer-related file opens in one spot?

[jam, 2015/06/09 01:12:46]

Hi, please work with someone on the android side to figure out if this can be
done in content and not in chrome.

[Yaron, 2015/06/09 03:39:40]

Hmm. I definitely touched the crash fd code and it had to be done in chrome
layer because content doesn't deal with breakpad. I'm pretty sure that predated
the ICU fd passing and they probably just mirrored crash. I can take a deeper
look when I'm in tomorrow. 

+
 #else
   int crash_signal_fd = GetCrashSignalFD(command_line);
   if (crash_signal_fd >= 0) {