[build] Conditionally print to stdout on Android

This adds a gyp/gn variable to control printing to stdout
on Android. This is false by default and true for all
v8 stand-alone android bots.

BUG=chromium:629806

Review-Url: https://codereview.chromium.org/2183063002
Cr-Commit-Position: refs/heads/master@{#38253}

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.

gypfiles/standalone.gypi

@@ -1116,7 +1116,6 @@
       'target_defaults': {
         'defines': [
           'ANDROID',
-          'V8_ANDROID_LOG_STDOUT',
         ],
         'configurations': {
           'Release': {

gypfiles/toolchain.gypi

@@ -57,6 +57,9 @@
     # Similar to the ARM hard float ABI but on MIPS.
     'v8_use_mips_abi_hardfloat%': 'true',
 
+    # Print to stdout on Android.
+    'v8_android_log_stdout%': 0,
+
     # Force disable libstdc++ debug mode.
     'disable_glibcxx_debug%': 0,
 
@@ -1082,6 +1085,11 @@
            }],
          ],
       }],
+      ['OS=="android" and v8_android_log_stdout==1', {
+        'defines': [
+          'V8_ANDROID_LOG_STDOUT',
+        ],
+      }],
       ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
          or OS=="netbsd" or OS=="qnx" or OS=="aix"', {
         'conditions': [

infra/mb/mb_config.pyl

@@ -389,8 +389,8 @@
 
   'mixins': {
     'android': {
-      'gn_args': 'target_os="android"',
-      'gyp_defines': 'OS=android',
+      'gn_args': 'target_os="android" v8_android_log_stdout=true',
+      'gyp_defines': 'OS=android v8_android_log_stdout=1',
     },
 
     'arm': {