Revert of [Android] Add a java.lang.System wrapper. (patchset #2 id:20001 of https://codereview.chromium.org/1283543003/ )

Reason for revert:
This doesn't actually work.

Original issue's description:
> [Android] Add a java.lang.System wrapper.
>
> Add a basic JNI wrapper for java.lang.System. Expose just the
> getProperty() method, eliminating a deprecated __system_property_get
> usage as well as a seperate System.getProperty wrapper.
>
> The remaining uses of __system_property_get will be removed in
> https://codereview.chromium.org/1236283002/.
>
> BUG=392196, 392191
>
> Committed: https://crrev.com/130c6bf9db16a69fca8488da8e15e978470e7e8b
> Cr-Commit-Position: refs/heads/master@{#343245}

TBR=rmcilroy@chromium.org,danakj@chromium.org,davidben@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=392196, 392191

Review URL: https://codereview.chromium.org/1294883002

Cr-Commit-Position: refs/heads/master@{#343430}

9 files changed, 28 insertions, 92 deletions

diff --git a/base/BUILD.gn b/base/BUILD.gn
index f2b659a..ccb580f 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -96,8 +96,6 @@ component("base") {
     "android/java_handler_thread.h",
     "android/java_runtime.cc",
     "android/java_runtime.h",
-    "android/java_system.cc",
-    "android/java_system.h",
     "android/jni_android.cc",
     "android/jni_android.h",
     "android/jni_array.cc",
@@ -1564,7 +1562,6 @@ if (is_android) {
 
     deps = [
       ":android_runtime_jni_headers",
-      ":android_system_jni_headers",
     ]
 
     jni_package = "base"
@@ -1576,12 +1573,6 @@ if (is_android) {
     classes = [ "java/lang/Runtime.class" ]
   }
 
-  # GYP: //base.gyp:android_system_jni_headers
-  generate_jar_jni("android_system_jni_headers") {
-    jni_package = "base"
-    classes = [ "java/lang/System.class" ]
-  }
-
   # GYP: //base.gyp:base_java
   android_library("base_java") {
     srcjar_deps = [
diff --git a/base/android/base_jni_registrar.cc b/base/android/base_jni_registrar.cc
index cedb0f2..752dcff 100644
--- a/base/android/base_jni_registrar.cc
+++ b/base/android/base_jni_registrar.cc
@@ -16,7 +16,6 @@
 #include "base/android/important_file_writer_android.h"
 #include "base/android/java_handler_thread.h"
 #include "base/android/java_runtime.h"
-#include "base/android/java_system.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_registrar.h"
 #include "base/android/jni_utils.h"
@@ -63,7 +62,6 @@ static RegistrationMethod kBaseRegisteredMethods[] = {
     {"RecordHistogram", base::android::RegisterRecordHistogram},
     {"RecordUserAction", base::android::RegisterRecordUserAction},
     {"Runtime", base::android::JavaRuntime::Register},
-    {"System", base::android::JavaSystem::Register},
     {"SystemMessageHandler", base::MessagePumpForUI::RegisterBindings},
     {"SysUtils", base::android::SysUtils::Register},
     {"ThreadUtils", base::RegisterThreadUtils},
diff --git a/base/android/java_system.cc b/base/android/java_system.cc
deleted file mode 100644
index 1c4e518..0000000
--- a/base/android/java_system.cc
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright (c) 2015 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.
-
-#include "base/android/java_system.h"
-
-#include "base/android/jni_string.h"
-#include "jni/System_jni.h"
-
-namespace base {
-namespace android {
-
-bool JavaSystem::Register(JNIEnv* env) {
-  return JNI_System::RegisterNativesImpl(env);
-}
-
-// static
-std::string JavaSystem::GetProperty(const base::StringPiece& property_name) {
-  DCHECK(!property_name.empty());
-  JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jstring> jproperty_name =
-      ConvertUTF8ToJavaString(env, property_name);
-  ScopedJavaLocalRef<jstring> jproperty =
-      JNI_System::Java_System_getPropertyJLS_JLS(env, jproperty_name.obj());
-  return jproperty.is_null() ? std::string()
-                             : ConvertJavaStringToUTF8(env, jproperty.obj());
-}
-
-}  // namespace android
-}  // namespace base
diff --git a/base/android/java_system.h b/base/android/java_system.h
deleted file mode 100644
index bab7257..0000000
--- a/base/android/java_system.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright (c) 2015 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.
-
-#ifndef BASE_ANDROID_JAVA_SYSTEM_H_
-#define BASE_ANDROID_JAVA_SYSTEM_H_
-
-#include <string>
-
-#include "base/android/jni_android.h"
-#include "base/base_export.h"
-#include "base/strings/string_piece.h"
-
-namespace base {
-namespace android {
-
-// Wrapper class for using the java.lang.System object from jni.
-class BASE_EXPORT JavaSystem {
- public:
-  // Registers the jni class (once per process).
-  static bool Register(JNIEnv* env);
-
-  // See java.lang.System.getProperty().
-  static std::string GetProperty(const base::StringPiece& stroperty_name);
-};
-
-}  // namespace android
-}  // namespace base
-
-#endif  // BASE_ANDROID_JAVA_SYSTEM_H_
diff --git a/base/base.gyp b/base/base.gyp
index f5d0fbd..4a558d8 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -1381,7 +1381,6 @@
           },
           'dependencies': [
             'android_runtime_jni_headers',
-            'android_system_jni_headers',
           ],
           'includes': [ '../build/jni_generator.gypi' ],
         },
@@ -1396,16 +1395,6 @@
           'includes': [ '../build/jar_file_jni_generator.gypi' ],
         },
         {
-          # GN: //base:android_system_jni_headers
-          'target_name': 'android_system_jni_headers',
-          'type': 'none',
-          'variables': {
-             'jni_gen_package': 'base',
-             'input_java_class': 'java/lang/System.class',
-           },
-          'includes': [ '../build/jar_file_jni_generator.gypi' ],
-        },
-        {
           # TODO(GN)
           'target_name': 'base_unittests_jni_headers',
           'type': 'none',
diff --git a/base/base.gypi b/base/base.gypi
index c982a13..cce8e44 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -50,8 +50,6 @@
           'android/java_handler_thread.h',
           'android/java_runtime.cc',
           'android/java_runtime.h',
-          'android/java_system.cc',
-          'android/java_system.h',
           'android/jni_android.cc',
           'android/jni_android.h',
           'android/jni_array.cc',
diff --git a/net/android/java/src/org/chromium/net/ProxyChangeListener.java b/net/android/java/src/org/chromium/net/ProxyChangeListener.java
index f3e9330..7df2d3b 100644
--- a/net/android/java/src/org/chromium/net/ProxyChangeListener.java
+++ b/net/android/java/src/org/chromium/net/ProxyChangeListener.java
@@ -73,6 +73,11 @@ public class ProxyChangeListener {
     }
 
     @CalledByNative
+    public static String getProperty(String property) {
+        return System.getProperty(property);
+    }
+
+    @CalledByNative
     public void start(long nativePtr) {
         assert mNativePtr == 0;
         mNativePtr = nativePtr;
diff --git a/net/dns/dns_config_service_posix.cc b/net/dns/dns_config_service_posix.cc
index b6ab022..02877e7 100644
--- a/net/dns/dns_config_service_posix.cc
+++ b/net/dns/dns_config_service_posix.cc
@@ -30,7 +30,7 @@
 #endif
 
 #if defined(OS_ANDROID)
-#include "base/android/java_system.h"
+#include <sys/system_properties.h>
 #include "net/base/network_change_notifier.h"
 #endif
 
@@ -154,14 +154,22 @@ ConfigParsePosixResult ReadDnsConfig(DnsConfig* config) {
   return result;
 }
 #else  // defined(OS_ANDROID)
-// Theoretically, this is bad. The DNS system properties are implementation
-// details that may disappear in future Android releases. Practically, the DNS
-// code (and its clients) are already robust against failing to get the DNS
+// Theoretically, this is bad. __system_property_get is not a supported API
+// (but it's currently visible to anyone using Bionic), and the properties
+// are implementation details that may disappear in future Android releases.
+// Practically, libcutils provides property_get, which is a public API, and the
+// DNS code (and its clients) are already robust against failing to get the DNS
 // config for whatever reason, so the properties can disappear and the world
 // won't end.
+// TODO(ttuttle): Depend on libcutils, then switch this (and other uses of
+//                __system_property_get) to property_get.
 ConfigParsePosixResult ReadDnsConfig(DnsConfig* dns_config) {
-  std::string dns1_string = base::android::JavaSystem::GetProperty("net.dns1");
-  std::string dns2_string = base::android::JavaSystem::GetProperty("net.dns2");
+   std::string dns1_string, dns2_string;
+  char property_value[PROP_VALUE_MAX];
+  __system_property_get("net.dns1", property_value);
+  dns1_string = property_value;
+  __system_property_get("net.dns2", property_value);
+  dns2_string = property_value;
   if (dns1_string.length() == 0 && dns2_string.length() == 0)
     return CONFIG_PARSE_POSIX_NO_NAMESERVERS;
 
diff --git a/net/proxy/proxy_config_service_android.cc b/net/proxy/proxy_config_service_android.cc
index e47670d..66065fb 100644
--- a/net/proxy/proxy_config_service_android.cc
+++ b/net/proxy/proxy_config_service_android.cc
@@ -4,7 +4,8 @@
 
 #include "net/proxy/proxy_config_service_android.h"
 
-#include "base/android/java_system.h"
+#include <sys/system_properties.h>
+
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/basictypes.h"
@@ -155,8 +156,14 @@ void GetLatestProxyConfigInternal(const GetPropertyCallback& get_property,
 }
 
 std::string GetJavaProperty(const std::string& property) {
+  // Use Java System.getProperty to get configuration information.
   // TODO(pliard): Conversion to/from UTF8 ok here?
-  return base::android::JavaSystem::GetProperty(property);
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jstring> str = ConvertUTF8ToJavaString(env, property);
+  ScopedJavaLocalRef<jstring> result =
+      Java_ProxyChangeListener_getProperty(env, str.obj());
+  return result.is_null() ?
+      std::string() : ConvertJavaStringToUTF8(env, result.obj());
 }
 
 void CreateStaticProxyConfig(const std::string& host,