[Android] Roll to NDK r12b.

build/config/android/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 assert(is_android)
 
 # This is included by reference in the //build/config/compiler config that
@@ skipping 103 matching lines @@
   lib_dirs = [ android_libcpp_lib_dir ]
 
   # The libc++ runtime library (must come first).
   # ASan needs to dynamically link to libc++ even in static builds so
   # that it can interpose operator new.
   if (is_component_build || is_asan) {
     libs = [ "c++_shared" ]
   } else {
     libs = [ "c++_static" ]
   }
+  libs += [
+    "c++abi",

[agrieve, 2016/09/04 00:44:32]

Might need to update cpplib_* with these extra libs as well:
https://cs.chromium.org/chromium/src/build/android/BUILD.gn?q=c%5C%2B%5C%2B_s...

[jbudorick, 2016/09/05 16:33:03]

I don't think that's necessary here; libc++_shared is the only .so. Everything
else is a static library.

+    "android_support",
+  ]
+
+  if (current_cpu == "arm") {

[agrieve, 2016/09/04 00:44:32]

This raises an eyebrow (needs a comment). Why only on arm? Could this be moved
to the component(s) that require it?

[jbudorick, 2016/09/05 16:33:03]

Comment added. libc++ requires it, but only on arm.
https://chromium.googlesource.com/android_ndk/+/a0190968500138134251e1c0e264d...

+    libs += [ "unwind" ]
+  }
 
   # Manually link the libgcc.a that the cross compiler uses. This is
   # absolute because the linker will look inside the sysroot if it's not.
   libs += [
     rebase_path(android_libgcc_file),
     "c",
   ]
 
   # Clang with libc++ does not require an explicit atomic library reference.
   if (!is_clang) {
@@ skipping 54 matching lines @@
 
       # Avoid errors with current NDK:
       # "third_party/android_tools/ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/include/arm_neon.h:3426:3: error: argument must be a constant"
       "-finstrument-functions-exclude-file-list=arm_neon.h",
     ]
   }
 }
 
 config("no_cygprofile_instrumentation") {
 }