[Android] Roll to NDK r12b.

build/config/android/config.gni

Index: build/config/android/config.gni
diff --git a/build/config/android/config.gni b/build/config/android/config.gni
index fd222691743bd59f696f438c9b144928ad1626af..6a16eb2d68bc82f3c147fcd0ec9e2c2247297525 100644
--- a/build/config/android/config.gni
+++ b/build/config/android/config.gni
@@ -26,8 +26,8 @@ if (is_android) {
 
   if (!defined(default_android_ndk_root)) {
     default_android_ndk_root = "//third_party/android_tools/ndk"
-    default_android_ndk_version = "r10e"
-    default_android_ndk_major_version = "10"
+    default_android_ndk_version = "r12b"
+    default_android_ndk_major_version = "12"
   } else {
     assert(defined(default_android_ndk_version))
     assert(defined(default_android_ndk_major_version))
@@ -210,6 +210,7 @@ if (is_android) {
   # Toolchain root directory for each build. The actual binaries are inside
   # a "bin" directory inside of these.
   _android_toolchain_version = "4.9"
+  _android_toolchain_detailed_version = "4.9.x"
   x86_android_toolchain_root = "$android_ndk_root/toolchains/x86-${_android_toolchain_version}/prebuilt/${android_host_os}-${android_host_arch}"
   arm_android_toolchain_root = "$android_ndk_root/toolchains/arm-linux-androideabi-${_android_toolchain_version}/prebuilt/${android_host_os}-${android_host_arch}"
   mips_android_toolchain_root = "$android_ndk_root/toolchains/mipsel-linux-android-${_android_toolchain_version}/prebuilt/${android_host_os}-${android_host_arch}"
@@ -224,32 +225,32 @@ if (is_android) {
     android_prebuilt_arch = "android-x86"
     _binary_prefix = "i686-linux-android"
     android_toolchain_root = "$x86_android_toolchain_root"
-    android_libgcc_file = "$android_toolchain_root/lib/gcc/i686-linux-android/${_android_toolchain_version}/libgcc.a"
+    android_libgcc_file = "$android_toolchain_root/lib/gcc/i686-linux-android/${_android_toolchain_detailed_version}/libgcc.a"
   } else if (current_cpu == "arm") {
     android_prebuilt_arch = "android-arm"
     _binary_prefix = "arm-linux-androideabi"
     android_toolchain_root = "$arm_android_toolchain_root"
-    android_libgcc_file = "$android_toolchain_root/lib/gcc/arm-linux-androideabi/${_android_toolchain_version}/libgcc.a"
+    android_libgcc_file = "$android_toolchain_root/lib/gcc/arm-linux-androideabi/${_android_toolchain_detailed_version}/libgcc.a"
   } else if (current_cpu == "mipsel") {
     android_prebuilt_arch = "android-mips"
     _binary_prefix = "mipsel-linux-android"
     android_toolchain_root = "$mips_android_toolchain_root"
-    android_libgcc_file = "$android_toolchain_root/lib/gcc/mipsel-linux-android/${_android_toolchain_version}/libgcc.a"
+    android_libgcc_file = "$android_toolchain_root/lib/gcc/mipsel-linux-android/${_android_toolchain_detailed_version}/libgcc.a"
   } else if (current_cpu == "x64") {
     android_prebuilt_arch = "android-x86_64"
     _binary_prefix = "x86_64-linux-android"
     android_toolchain_root = "$x86_64_android_toolchain_root"
-    android_libgcc_file = "$android_toolchain_root/lib/gcc/x86_64-linux-android/${_android_toolchain_version}/libgcc.a"
+    android_libgcc_file = "$android_toolchain_root/lib/gcc/x86_64-linux-android/${_android_toolchain_detailed_version}/libgcc.a"
   } else if (current_cpu == "arm64") {
     android_prebuilt_arch = "android-arm64"
     _binary_prefix = "aarch64-linux-android"
     android_toolchain_root = "$arm64_android_toolchain_root"
-    android_libgcc_file = "$android_toolchain_root/lib/gcc/aarch64-linux-android/${_android_toolchain_version}/libgcc.a"
+    android_libgcc_file = "$android_toolchain_root/lib/gcc/aarch64-linux-android/${_android_toolchain_detailed_version}/libgcc.a"
   } else if (current_cpu == "mips64el") {
     android_prebuilt_arch = "android-mips64"
     _binary_prefix = "mips64el-linux-android"
     android_toolchain_root = "$mips64_android_toolchain_root"
-    android_libgcc_file = "$android_toolchain_root/lib/gcc/mips64el-linux-android/${_android_toolchain_version}/libgcc.a"
+    android_libgcc_file = "$android_toolchain_root/lib/gcc/mips64el-linux-android/${_android_toolchain_detailed_version}/libgcc.a"
   } else {
     assert(false, "Need android libgcc support for your target arch.")
   }