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

base/i18n/icu_util.cc

Index: base/i18n/icu_util.cc
diff --git a/base/i18n/icu_util.cc b/base/i18n/icu_util.cc
index a9f0b129633cd596934b8cf7d680d1fcca7f7a8a..4cea9d2d6fa99cb3283ec69ef1fc6f1ff4cb1bfd 100644
--- a/base/i18n/icu_util.cc
+++ b/base/i18n/icu_util.cc
@@ -23,6 +23,10 @@
 #include "third_party/icu/source/i18n/unicode/timezone.h"
 #endif
 
+#if defined(OS_ANDROID)
+#include "base/android/apk_assets.h"
+#endif
+
 #if defined(OS_MACOSX)
 #include "base/mac/foundation_util.h"
 #endif
@@ -118,7 +122,16 @@ bool InitializeICU() {
 #elif (ICU_UTIL_DATA_IMPL == ICU_UTIL_DATA_STATIC)
   // The ICU data is statically linked.
   result = true;
-#elif (ICU_UTIL_DATA_IMPL == ICU_UTIL_DATA_FILE)
+#elif (ICU_UTIL_DATA_IMPL == ICU_UTIL_DATA_FILE) && OS_ANDROID

[Yaron, 2015/06/02 14:28:01]

defined(OS_ANDROID)

[agrieve, 2015/06/02 17:24:40]

Done.

+  base::MemoryMappedFile::Region pak_region;
+  int pak_fd = base::android::OpenApkAsset(kIcuDataFileName, &pak_region);
+  CHECK(pak_fd != -1);
+
+#if !defined(NDEBUG)

[Yaron, 2015/06/02 14:28:01]

Yikes. This is pretty awkward (to be fair this function is a mess even before
you getting here).

If you look at the comment in icu_util.h, it mentions that android is already
supposed to call InitializeICUWithFileDescriptor. Then looking at
content_main_runner.cc, I see it trying to initialize using an fd. I guess that
part only works on the renderer process?

One option would be to codify this more meaningfully in content_main_runner.cc.
There you have access to |process_type| and can specify to do this for browser
process, but load from previously initialized fds for child processes.

However, I also see many other callers to InitializeICU. Have you tried running
native tests? It looks like they'll now try and load icu from the apk - is it
packaged for them? Same question for content_shell.

[agrieve, 2015/06/02 17:24:40]

Agree it's awkward :S

InitializeICU is called from many places (tests, remoting, demo apps), so I
think it makes sense to continue to support it.

The native tests do also load right from the apk. I'm hoping to make all asset
loading to be consistent across targets (never extract and always mmap).

+  g_called_once = false;
+#endif
+  result = InitializeICUWithFileDescriptor(pak_fd, pak_region);
+#elif (ICU_UTIL_DATA_IMPL == ICU_UTIL_DATA_FILE) && !OS_ANDROID

[Yaron, 2015/06/02 14:28:01]

!defined(OS_ANDROID)

[agrieve, 2015/06/02 17:24:40]

Done.

   // If the ICU data directory is set, ICU won't actually load the data until
   // it is needed.  This can fail if the process is sandboxed at that time.
   // Instead, we map the file in and hand off the data so the sandbox won't
@@ -137,8 +150,6 @@ bool InitializeICU() {
     wcscpy_s(tmp_buffer, data_path.value().c_str());
     debug::Alias(tmp_buffer);
     CHECK(path_ok);  // TODO(scottmg): http://crbug.com/445616
-#elif defined(OS_ANDROID)
-    bool path_ok = PathService::Get(DIR_ANDROID_APP_DATA, &data_path);
 #else
     // For now, expect the data file to be alongside the executable.
     // This is sufficient while we work on unit tests, but will eventually