Update Chomium's build files to work w/ latest GN binaries.

build/toolchain/android/BUILD.gn

Index: build/toolchain/android/BUILD.gn
diff --git a/build/toolchain/android/BUILD.gn b/build/toolchain/android/BUILD.gn
index d21ed275020bd72b8fd085aae3520bb159a905f1..90b976c6d876c2d8266ebe2b6817c6ff47db1f8a 100644
--- a/build/toolchain/android/BUILD.gn
+++ b/build/toolchain/android/BUILD.gn
@@ -18,7 +18,7 @@ import("//build/toolchain/gcc_toolchain.gni")
 #      Subdirectory inside of android_ndk_sysroot where libs go.
 #  - tool_prefix
 #      Prefix to be added to the tool names.
-#  - toolchain_cpu_arch
+#  - toolchain_cpu
 #      Same as gcc_toolchain
 template("android_gcc_toolchain") {
   gcc_toolchain(target_name) {
@@ -51,7 +51,7 @@ template("android_gcc_toolchain") {
     ld = cxx
 
     toolchain_os = "android"
-    toolchain_cpu_arch = invoker.toolchain_cpu_arch
+    toolchain_cpu = invoker.toolchain_cpu
 
     # We make the assumption that the gcc_toolchain will produce a soname with
     # the following definition.
@@ -85,7 +85,7 @@ android_gcc_toolchain("x86") {
   android_ndk_lib_dir = "usr/lib"
 
   tool_prefix = "$x86_android_toolchain_root/bin/i686-linux-android-"
-  toolchain_cpu_arch = "x86"
+  toolchain_cpu = "x86"
 }
 
 android_gcc_toolchain("arm") {
@@ -93,7 +93,7 @@ android_gcc_toolchain("arm") {
   android_ndk_lib_dir = "usr/lib"
 
   tool_prefix = "$arm_android_toolchain_root/bin/arm-linux-androideabi-"
-  toolchain_cpu_arch = "arm"
+  toolchain_cpu = "arm"
 }
 
 android_gcc_toolchain("mipsel") {
@@ -101,5 +101,5 @@ android_gcc_toolchain("mipsel") {
   android_ndk_lib_dir = "usr/lib"
 
   tool_prefix = "$mips_android_toolchain_root/bin/mipsel-linux-android-"
-  toolchain_cpu_arch = "mipsel"
+  toolchain_cpu = "mipsel"
 }