[build] Conditionally print to stdout on Android

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 2972224d8e8b4bed1e6bea543fb4b8fff2de456e..9dad9cd2a0354a92b95a32fe6bafaef0957b0ea0 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -19,6 +19,9 @@ import("//build_overrides/v8.gni")
 import("snapshot_toolchain.gni")
 
 declare_args() {
+  # Print to stdout on Android.
+  v8_android_log_stdout = false
+
   # Sets -DVERIFY_HEAP.
   v8_enable_verify_heap = false
 
@@ -313,6 +316,9 @@ config("toolchain") {
       ldflags += [ "/STACK:2097152" ]
     }
   }
+  if (is_android && v8_android_log_stdout) {
+    defines += [ "V8_ANDROID_LOG_STDOUT" ]
+  }
 
   # TODO(jochen): Support v8_enable_prof on Windows.
   # TODO(jochen): Add support for compiling with simulators.