Android: lazy initialization for method id.

Rather than requiring early registration for all method id, we can initialize
them lazily as required.
This solves the problem of building against SDK X but running against X - 1.
Also adds a microbenchmark to ensure there are no considerable regressions.
Results are a bit variable, but it hovers over:
[ERROR:jni_android_unittest.cc(125)] JNI LazyMethodIDCall (us) 1983
[ERROR:jni_android_unittest.cc(127)] JNI MethodIDCall (us) 1862

BUG=152987
TEST=JNIAndroidMicrobenchmark.MethodId
TBR=akalin

Review URL: https://chromiumcodereview.appspot.com/11038015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@162186 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 357 insertions, 376 deletions

diff --git a/base/android/jni_generator/golden_sample_for_tests_jni.h b/base/android/jni_generator/golden_sample_for_tests_jni.h
index b80f8f4..08f25a7 100644
--- a/base/android/jni_generator/golden_sample_for_tests_jni.h
+++ b/base/android/jni_generator/golden_sample_for_tests_jni.h
@@ -66,7 +66,7 @@ static jdouble MethodOtherP0(JNIEnv* env, jobject obj,
     jint nativePtr) {
   DCHECK(nativePtr) << "MethodOtherP0";
   CPPClass::InnerClass* native =
-        reinterpret_cast<CPPClass::InnerClass*>(nativePtr);
+      reinterpret_cast<CPPClass::InnerClass*>(nativePtr);
   return native->MethodOtherP0(env, obj);
 }
 
@@ -77,147 +77,147 @@ static jstring InnerMethod(JNIEnv* env, jobject obj,
   return native->InnerMethod(env, obj).Release();
 }
 
-static jmethodID g_SampleForTests_javaMethod = 0;
+static base::subtle::AtomicWord g_SampleForTests_javaMethod = 0;
 static jint Java_SampleForTests_javaMethod(JNIEnv* env, jobject obj, jint foo,
     jint bar) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_SampleForTests_clazz);
-  DCHECK(g_SampleForTests_javaMethod);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_SampleForTests_clazz,
+      "javaMethod",
+
+"("
+"I"
+"I"
+")"
+"I",
+      &g_SampleForTests_javaMethod);
+
   jint ret =
     env->CallIntMethod(obj,
-      g_SampleForTests_javaMethod, foo, bar);
+      method_id, foo, bar);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_SampleForTests_staticJavaMethod = 0;
+static base::subtle::AtomicWord g_SampleForTests_staticJavaMethod = 0;
 static jboolean Java_SampleForTests_staticJavaMethod(JNIEnv* env) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_SampleForTests_clazz);
-  DCHECK(g_SampleForTests_staticJavaMethod);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_STATIC>(
+      env, g_SampleForTests_clazz,
+      "staticJavaMethod",
+
+"("
+")"
+"Z",
+      &g_SampleForTests_staticJavaMethod);
+
   jboolean ret =
     env->CallStaticBooleanMethod(g_SampleForTests_clazz,
-      g_SampleForTests_staticJavaMethod);
+      method_id);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_SampleForTests_packagePrivateJavaMethod = 0;
+static base::subtle::AtomicWord g_SampleForTests_packagePrivateJavaMethod = 0;
 static void Java_SampleForTests_packagePrivateJavaMethod(JNIEnv* env, jobject
     obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_SampleForTests_clazz);
-  DCHECK(g_SampleForTests_packagePrivateJavaMethod);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_SampleForTests_clazz,
+      "packagePrivateJavaMethod",
+
+"("
+")"
+"V",
+      &g_SampleForTests_packagePrivateJavaMethod);
 
   env->CallVoidMethod(obj,
-      g_SampleForTests_packagePrivateJavaMethod);
+      method_id);
   base::android::CheckException(env);
 
 }
 
-static jmethodID g_SampleForTests_methodThatThrowsException = 0;
+static base::subtle::AtomicWord g_SampleForTests_methodThatThrowsException = 0;
 static void Java_SampleForTests_methodThatThrowsException(JNIEnv* env, jobject
     obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_SampleForTests_clazz);
-  DCHECK(g_SampleForTests_methodThatThrowsException);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_SampleForTests_clazz,
+      "methodThatThrowsException",
+
+"("
+")"
+"V",
+      &g_SampleForTests_methodThatThrowsException);
 
   env->CallVoidMethod(obj,
-      g_SampleForTests_methodThatThrowsException);
+      method_id);
 
 }
 
-static jmethodID g_InnerClass_JavaInnerMethod = 0;
+static base::subtle::AtomicWord g_InnerClass_JavaInnerMethod = 0;
 static jfloat Java_InnerClass_JavaInnerMethod(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InnerClass_clazz);
-  DCHECK(g_InnerClass_JavaInnerMethod);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InnerClass_clazz,
+      "JavaInnerMethod",
+
+"("
+")"
+"F",
+      &g_InnerClass_JavaInnerMethod);
+
   jfloat ret =
     env->CallFloatMethod(obj,
-      g_InnerClass_JavaInnerMethod);
+      method_id);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InnerClass_javaInnerFunction = 0;
+static base::subtle::AtomicWord g_InnerClass_javaInnerFunction = 0;
 static void Java_InnerClass_javaInnerFunction(JNIEnv* env) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InnerClass_clazz);
-  DCHECK(g_InnerClass_javaInnerFunction);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_STATIC>(
+      env, g_InnerClass_clazz,
+      "javaInnerFunction",
+
+"("
+")"
+"V",
+      &g_InnerClass_javaInnerFunction);
 
   env->CallStaticVoidMethod(g_InnerClass_clazz,
-      g_InnerClass_javaInnerFunction);
+      method_id);
   base::android::CheckException(env);
 
 }
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
+// Step 3: RegisterNatives.
+
+static bool RegisterNativesImpl(JNIEnv* env) {
+
   g_InnerClass_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
       base::android::GetUnscopedClass(env, kInnerClassClassPath)));
   g_SampleForTests_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
       base::android::GetUnscopedClass(env, kSampleForTestsClassPath)));
-  g_SampleForTests_javaMethod =
-      base::android::GetMethodID(
-          env, g_SampleForTests_clazz,
-          "javaMethod",
-
-"("
-"I"
-"I"
-")"
-"I");
-
-  g_SampleForTests_staticJavaMethod =
-      base::android::GetStaticMethodID(
-          env, g_SampleForTests_clazz,
-          "staticJavaMethod",
-
-"("
-")"
-"Z");
-
-  g_SampleForTests_packagePrivateJavaMethod =
-      base::android::GetMethodID(
-          env, g_SampleForTests_clazz,
-          "packagePrivateJavaMethod",
-
-"("
-")"
-"V");
-
-  g_SampleForTests_methodThatThrowsException =
-      base::android::GetMethodID(
-          env, g_SampleForTests_clazz,
-          "methodThatThrowsException",
-
-"("
-")"
-"V");
-
-  g_InnerClass_JavaInnerMethod =
-      base::android::GetMethodID(
-          env, g_InnerClass_clazz,
-          "JavaInnerMethod",
-
-"("
-")"
-"F");
-
-  g_InnerClass_javaInnerFunction =
-      base::android::GetStaticMethodID(
-          env, g_InnerClass_clazz,
-          "javaInnerFunction",
-
-"("
-")"
-"V");
-
-}
-
-static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
-
   static const JNINativeMethod kMethodsInnerClass[] = {
     { "nativeInnerFunction",
 "("
diff --git a/base/android/jni_generator/jni_generator.py b/base/android/jni_generator/jni_generator.py
index f8df00a..afc2389 100755
--- a/base/android/jni_generator/jni_generator.py
+++ b/base/android/jni_generator/jni_generator.py
@@ -603,13 +603,9 @@ $FORWARD_DECLARATIONS
 // Step 2: method stubs.
 $METHOD_STUBS
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-$GET_METHOD_IDS_IMPL
-}
+// Step 3: RegisterNatives.
 
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 $REGISTER_NATIVES_IMPL
   return true;
 }
@@ -626,7 +622,6 @@ $CLOSE_NAMESPACE
         'FORWARD_DECLARATIONS': self.GetForwardDeclarationsString(),
         'METHOD_STUBS': self.GetMethodStubsString(),
         'OPEN_NAMESPACE': self.GetOpenNamespaceString(),
-        'GET_METHOD_IDS_IMPL': self.GetMethodIDsImplString(),
         'REGISTER_NATIVES_IMPL': self.GetRegisterNativesImplString(),
         'CLOSE_NAMESPACE': self.GetCloseNamespaceString(),
         'HEADER_GUARD': self.header_guard,
@@ -662,13 +657,6 @@ $CLOSE_NAMESPACE
         ret += [self.GetKMethodArrayEntry(native)]
     return '\n'.join(ret)
 
-  def GetMethodIDsImplString(self):
-    ret = []
-    ret += [self.GetFindClasses()]
-    for called_by_native in self.called_by_natives:
-      ret += [self.GetMethodIDImpl(called_by_native)]
-    return '\n'.join(ret)
-
   def GetRegisterNativesImplString(self):
     """Returns the implementation for RegisterNatives."""
     template = Template("""\
@@ -684,7 +672,7 @@ ${KMETHODS}
     return false;
   }
 """)
-    ret = []
+    ret = [self.GetFindClasses()]
     all_classes = self.GetUniqueClasses(self.natives)
     all_classes[self.class_name] = self.fully_qualified_class
     for clazz in all_classes:
@@ -793,14 +781,15 @@ ${FUNCTION_SIGNATURE} {""")
 ${FUNCTION_SIGNATURE} __attribute__ ((unused));
 ${FUNCTION_SIGNATURE} {""")
     template = Template("""
-static jmethodID g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME} = 0;
+static base::subtle::AtomicWord g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME} = 0;
 ${FUNCTION_HEADER}
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_${JAVA_CLASS}_clazz);
-  DCHECK(g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME});
+  jmethodID method_id =
+    ${GET_METHOD_ID_IMPL}
   ${RETURN_DECLARATION}
   ${PRE_CALL}env->${ENV_CALL}(${FIRST_PARAM_IN_CALL},
-      g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME}${PARAMS_IN_CALL})${POST_CALL};
+      method_id${PARAMS_IN_CALL})${POST_CALL};
   ${CHECK_EXCEPTION}
   ${RETURN_CLAUSE}
 }""")
@@ -855,6 +844,7 @@ ${FUNCTION_HEADER}
         'PARAMS_IN_CALL': params_for_call,
         'METHOD_ID_VAR_NAME': called_by_native.method_id_var_name,
         'CHECK_EXCEPTION': check_exception,
+        'GET_METHOD_ID_IMPL': self.GetMethodIDImpl(called_by_native)
     }
     values['FUNCTION_SIGNATURE'] = (
         function_signature_template.substitute(values))
@@ -924,11 +914,12 @@ jclass g_${JAVA_CLASS}_clazz = NULL;""")
   def GetMethodIDImpl(self, called_by_native):
     """Returns the implementation of GetMethodID."""
     template = Template("""\
-  g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME} =
-      base::android::Get${STATIC}MethodID${SUFFIX}(
-          env, g_${JAVA_CLASS}_clazz,
-          "${JNI_NAME}",
-          ${JNI_SIGNATURE});
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_${STATIC}>(
+      env, g_${JAVA_CLASS}_clazz,
+      "${JNI_NAME}",
+      ${JNI_SIGNATURE},
+      &g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME});
 """)
     jni_name = called_by_native.name
     jni_return_type = called_by_native.return_type
@@ -939,8 +930,7 @@ jclass g_${JAVA_CLASS}_clazz = NULL;""")
         'JAVA_CLASS': called_by_native.java_class_name or self.class_name,
         'JNI_NAME': jni_name,
         'METHOD_ID_VAR_NAME': called_by_native.method_id_var_name,
-        'STATIC': 'Static' if called_by_native.static else '',
-        'SUFFIX': 'OrNull' if called_by_native.system_class else '',
+        'STATIC': 'STATIC' if called_by_native.static else 'INSTANCE',
         'JNI_SIGNATURE': JniSignature(called_by_native.params,
                                       jni_return_type,
                                       True)
diff --git a/base/android/jni_generator/jni_generator_tests.py b/base/android/jni_generator/jni_generator_tests.py
index 23efa02..4c345ed 100755
--- a/base/android/jni_generator/jni_generator_tests.py
+++ b/base/android/jni_generator/jni_generator_tests.py
@@ -315,19 +315,16 @@ static void GotOrientation(JNIEnv* env, jobject obj,
     jdouble gamma) {
   DCHECK(nativeDataFetcherImplAndroid) << "GotOrientation";
   DataFetcherImplAndroid* native =
-    reinterpret_cast<DataFetcherImplAndroid*>(nativeDataFetcherImplAndroid);
+      reinterpret_cast<DataFetcherImplAndroid*>(nativeDataFetcherImplAndroid);
   return native->GotOrientation(env, obj, alpha, beta, gamma);
 }
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kTestJniClassPath)));
-}
+// Step 3: RegisterNatives.
 
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 
+  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kTestJniClassPath)));
   static const JNINativeMethod kMethodsTestJni[] = {
     { "nativeInit",
 "("
@@ -481,15 +478,12 @@ static jint Init(JNIEnv* env, jobject obj);
 
 // Step 2: method stubs.
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kTestJniClassPath)));
-}
+// Step 3: RegisterNatives.
 
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 
+  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kTestJniClassPath)));
   static const JNINativeMethod kMethodsMyInnerClass[] = {
     { "nativeInit",
 "("
@@ -575,15 +569,12 @@ static jint Init(JNIEnv* env, jobject obj);
 
 // Step 2: method stubs.
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kTestJniClassPath)));
-}
+// Step 3: RegisterNatives.
 
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 
+  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kTestJniClassPath)));
   static const JNINativeMethod kMethodsMyOtherInnerClass[] = {
     { "nativeInit",
 "("
@@ -683,15 +674,12 @@ static jint Init(JNIEnv* env, jobject obj);
 
 // Step 2: method stubs.
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kTestJniClassPath)));
-}
+// Step 3: RegisterNatives.
 
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 
+  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kTestJniClassPath)));
   static const JNINativeMethod kMethodsMyOtherInnerClass[] = {
     { "nativeInit",
 "("
@@ -910,7 +898,7 @@ jclass g_InfoBar_clazz = NULL;
 
 // Step 2: method stubs.
 
-static jmethodID g_TestJni_showConfirmInfoBar = 0;
+static base::subtle::AtomicWord g_TestJni_showConfirmInfoBar = 0;
 static ScopedJavaLocalRef<jobject> Java_TestJni_showConfirmInfoBar(JNIEnv* env,
     jobject obj, jint nativeInfoBar,
     jstring buttonOk,
@@ -919,16 +907,30 @@ static ScopedJavaLocalRef<jobject> Java_TestJni_showConfirmInfoBar(JNIEnv* env,
     jobject icon) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_TestJni_clazz);
-  DCHECK(g_TestJni_showConfirmInfoBar);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_TestJni_clazz,
+      "showConfirmInfoBar",
+
+"("
+"I"
+"Ljava/lang/String;"
+"Ljava/lang/String;"
+"Ljava/lang/String;"
+"Landroid/graphics/Bitmap;"
+")"
+"Lcom/google/android/apps/chrome/infobar/InfoBarContainer$NativeInfoBar;",
+      &g_TestJni_showConfirmInfoBar);
+
   jobject ret =
     env->CallObjectMethod(obj,
-      g_TestJni_showConfirmInfoBar, nativeInfoBar, buttonOk, buttonCancel,
-          title, icon);
+      method_id, nativeInfoBar, buttonOk, buttonCancel, title, icon);
   base::android::CheckException(env);
   return ScopedJavaLocalRef<jobject>(env, ret);
 }
 
-static jmethodID g_TestJni_showAutoLoginInfoBar = 0;
+static base::subtle::AtomicWord g_TestJni_showAutoLoginInfoBar = 0;
 static ScopedJavaLocalRef<jobject> Java_TestJni_showAutoLoginInfoBar(JNIEnv*
     env, jobject obj, jint nativeInfoBar,
     jstring realm,
@@ -936,27 +938,50 @@ static ScopedJavaLocalRef<jobject> Java_TestJni_showAutoLoginInfoBar(JNIEnv*
     jstring args) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_TestJni_clazz);
-  DCHECK(g_TestJni_showAutoLoginInfoBar);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_TestJni_clazz,
+      "showAutoLoginInfoBar",
+
+"("
+"I"
+"Ljava/lang/String;"
+"Ljava/lang/String;"
+"Ljava/lang/String;"
+")"
+"Lcom/google/android/apps/chrome/infobar/InfoBarContainer$NativeInfoBar;",
+      &g_TestJni_showAutoLoginInfoBar);
+
   jobject ret =
     env->CallObjectMethod(obj,
-      g_TestJni_showAutoLoginInfoBar, nativeInfoBar, realm, account, args);
+      method_id, nativeInfoBar, realm, account, args);
   base::android::CheckException(env);
   return ScopedJavaLocalRef<jobject>(env, ret);
 }
 
-static jmethodID g_InfoBar_dismiss = 0;
+static base::subtle::AtomicWord g_InfoBar_dismiss = 0;
 static void Java_InfoBar_dismiss(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InfoBar_clazz);
-  DCHECK(g_InfoBar_dismiss);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InfoBar_clazz,
+      "dismiss",
+
+"("
+")"
+"V",
+      &g_InfoBar_dismiss);
 
   env->CallVoidMethod(obj,
-      g_InfoBar_dismiss);
+      method_id);
   base::android::CheckException(env);
 
 }
 
-static jmethodID g_TestJni_shouldShowAutoLogin = 0;
+static base::subtle::AtomicWord g_TestJni_shouldShowAutoLogin = 0;
 static jboolean Java_TestJni_shouldShowAutoLogin(JNIEnv* env, jobject
     contentView,
     jstring realm,
@@ -964,28 +989,53 @@ static jboolean Java_TestJni_shouldShowAutoLogin(JNIEnv* env, jobject
     jstring args) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_TestJni_clazz);
-  DCHECK(g_TestJni_shouldShowAutoLogin);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_STATIC>(
+      env, g_TestJni_clazz,
+      "shouldShowAutoLogin",
+
+"("
+"Lorg/chromium/content/browser/ContentViewCore;"
+"Ljava/lang/String;"
+"Ljava/lang/String;"
+"Ljava/lang/String;"
+")"
+"Z",
+      &g_TestJni_shouldShowAutoLogin);
+
   jboolean ret =
     env->CallStaticBooleanMethod(g_TestJni_clazz,
-      g_TestJni_shouldShowAutoLogin, contentView, realm, account, args);
+      method_id, contentView, realm, account, args);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_TestJni_openUrl = 0;
+static base::subtle::AtomicWord g_TestJni_openUrl = 0;
 static ScopedJavaLocalRef<jobject> Java_TestJni_openUrl(JNIEnv* env, jstring
     url) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_TestJni_clazz);
-  DCHECK(g_TestJni_openUrl);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_STATIC>(
+      env, g_TestJni_clazz,
+      "openUrl",
+
+"("
+"Ljava/lang/String;"
+")"
+"Ljava/io/InputStream;",
+      &g_TestJni_openUrl);
+
   jobject ret =
     env->CallStaticObjectMethod(g_TestJni_clazz,
-      g_TestJni_openUrl, url);
+      method_id, url);
   base::android::CheckException(env);
   return ScopedJavaLocalRef<jobject>(env, ret);
 }
 
-static jmethodID g_TestJni_activateHardwareAcceleration = 0;
+static base::subtle::AtomicWord g_TestJni_activateHardwareAcceleration = 0;
 static void Java_TestJni_activateHardwareAcceleration(JNIEnv* env, jobject obj,
     jboolean activated,
     jint iPid,
@@ -994,120 +1044,57 @@ static void Java_TestJni_activateHardwareAcceleration(JNIEnv* env, jobject obj,
     jint iSecondaryID) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_TestJni_clazz);
-  DCHECK(g_TestJni_activateHardwareAcceleration);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_TestJni_clazz,
+      "activateHardwareAcceleration",
+
+"("
+"Z"
+"I"
+"I"
+"I"
+"I"
+")"
+"V",
+      &g_TestJni_activateHardwareAcceleration);
 
   env->CallVoidMethod(obj,
-      g_TestJni_activateHardwareAcceleration, activated, iPid, iType,
-          iPrimaryID, iSecondaryID);
+      method_id, activated, iPid, iType, iPrimaryID, iSecondaryID);
   base::android::CheckException(env);
 
 }
 
-static jmethodID g_TestJni_uncheckedCall = 0;
+static base::subtle::AtomicWord g_TestJni_uncheckedCall = 0;
 static void Java_TestJni_uncheckedCall(JNIEnv* env, jobject obj, jint iParam) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_TestJni_clazz);
-  DCHECK(g_TestJni_uncheckedCall);
-
-  env->CallVoidMethod(obj,
-      g_TestJni_uncheckedCall, iParam);
-
-}
-
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kTestJniClassPath)));
-  g_InfoBar_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kInfoBarClassPath)));
-  g_TestJni_showConfirmInfoBar =
-      base::android::GetMethodID(
-          env, g_TestJni_clazz,
-          "showConfirmInfoBar",
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_TestJni_clazz,
+      "uncheckedCall",
 
 "("
 "I"
-"Ljava/lang/String;"
-"Ljava/lang/String;"
-"Ljava/lang/String;"
-"Landroid/graphics/Bitmap;"
 ")"
-"Lcom/google/android/apps/chrome/infobar/InfoBarContainer$NativeInfoBar;");
-
-  g_TestJni_showAutoLoginInfoBar =
-      base::android::GetMethodID(
-          env, g_TestJni_clazz,
-          "showAutoLoginInfoBar",
+"V",
+      &g_TestJni_uncheckedCall);
 
-"("
-"I"
-"Ljava/lang/String;"
-"Ljava/lang/String;"
-"Ljava/lang/String;"
-")"
-"Lcom/google/android/apps/chrome/infobar/InfoBarContainer$NativeInfoBar;");
-
-  g_InfoBar_dismiss =
-      base::android::GetMethodID(
-          env, g_InfoBar_clazz,
-          "dismiss",
-
-"("
-")"
-"V");
-
-  g_TestJni_shouldShowAutoLogin =
-      base::android::GetStaticMethodID(
-          env, g_TestJni_clazz,
-          "shouldShowAutoLogin",
-
-"("
-"Lorg/chromium/content/browser/ContentViewCore;"
-"Ljava/lang/String;"
-"Ljava/lang/String;"
-"Ljava/lang/String;"
-")"
-"Z");
-
-  g_TestJni_openUrl =
-      base::android::GetStaticMethodID(
-          env, g_TestJni_clazz,
-          "openUrl",
-
-"("
-"Ljava/lang/String;"
-")"
-"Ljava/io/InputStream;");
-
-  g_TestJni_activateHardwareAcceleration =
-      base::android::GetMethodID(
-          env, g_TestJni_clazz,
-          "activateHardwareAcceleration",
-
-"("
-"Z"
-"I"
-"I"
-"I"
-"I"
-")"
-"V");
-
-  g_TestJni_uncheckedCall =
-      base::android::GetMethodID(
-          env, g_TestJni_clazz,
-          "uncheckedCall",
-
-"("
-"I"
-")"
-"V");
+  env->CallVoidMethod(obj,
+      method_id, iParam);
 
 }
 
+// Step 3: RegisterNatives.
+
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 
+  g_TestJni_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kTestJniClassPath)));
+  g_InfoBar_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kInfoBarClassPath)));
   return true;
 }
 
@@ -1217,91 +1204,151 @@ namespace JNI_InputStream {
 
 // Step 2: method stubs.
 
-static jmethodID g_InputStream_available = 0;
+static base::subtle::AtomicWord g_InputStream_available = 0;
 static jint Java_InputStream_available(JNIEnv* env, jobject obj) __attribute__
     ((unused));
 static jint Java_InputStream_available(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_available);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "available",
+
+"("
+")"
+"I",
+      &g_InputStream_available);
+
   jint ret =
     env->CallIntMethod(obj,
-      g_InputStream_available);
+      method_id);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InputStream_close = 0;
+static base::subtle::AtomicWord g_InputStream_close = 0;
 static void Java_InputStream_close(JNIEnv* env, jobject obj) __attribute__
     ((unused));
 static void Java_InputStream_close(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_close);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "close",
+
+"("
+")"
+"V",
+      &g_InputStream_close);
 
   env->CallVoidMethod(obj,
-      g_InputStream_close);
+      method_id);
   base::android::CheckException(env);
 
 }
 
-static jmethodID g_InputStream_mark = 0;
+static base::subtle::AtomicWord g_InputStream_mark = 0;
 static void Java_InputStream_mark(JNIEnv* env, jobject obj, jint p0)
     __attribute__ ((unused));
 static void Java_InputStream_mark(JNIEnv* env, jobject obj, jint p0) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_mark);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "mark",
+
+"("
+"I"
+")"
+"V",
+      &g_InputStream_mark);
 
   env->CallVoidMethod(obj,
-      g_InputStream_mark, p0);
+      method_id, p0);
   base::android::CheckException(env);
 
 }
 
-static jmethodID g_InputStream_markSupported = 0;
+static base::subtle::AtomicWord g_InputStream_markSupported = 0;
 static jboolean Java_InputStream_markSupported(JNIEnv* env, jobject obj)
     __attribute__ ((unused));
 static jboolean Java_InputStream_markSupported(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_markSupported);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "markSupported",
+
+"("
+")"
+"Z",
+      &g_InputStream_markSupported);
+
   jboolean ret =
     env->CallBooleanMethod(obj,
-      g_InputStream_markSupported);
+      method_id);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InputStream_readI = 0;
+static base::subtle::AtomicWord g_InputStream_readI = 0;
 static jint Java_InputStream_readI(JNIEnv* env, jobject obj) __attribute__
     ((unused));
 static jint Java_InputStream_readI(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_readI);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "read",
+
+"("
+")"
+"I",
+      &g_InputStream_readI);
+
   jint ret =
     env->CallIntMethod(obj,
-      g_InputStream_readI);
+      method_id);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InputStream_readI_AB = 0;
+static base::subtle::AtomicWord g_InputStream_readI_AB = 0;
 static jint Java_InputStream_readI_AB(JNIEnv* env, jobject obj, jbyteArray p0)
     __attribute__ ((unused));
 static jint Java_InputStream_readI_AB(JNIEnv* env, jobject obj, jbyteArray p0) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_readI_AB);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "read",
+
+"("
+"[B"
+")"
+"I",
+      &g_InputStream_readI_AB);
+
   jint ret =
     env->CallIntMethod(obj,
-      g_InputStream_readI_AB, p0);
+      method_id, p0);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InputStream_readI_AB_I_I = 0;
+static base::subtle::AtomicWord g_InputStream_readI_AB_I_I = 0;
 static jint Java_InputStream_readI_AB_I_I(JNIEnv* env, jobject obj, jbyteArray
     p0,
     jint p1,
@@ -1312,161 +1359,105 @@ static jint Java_InputStream_readI_AB_I_I(JNIEnv* env, jobject obj, jbyteArray
     jint p2) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_readI_AB_I_I);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "read",
+
+"("
+"[B"
+"I"
+"I"
+")"
+"I",
+      &g_InputStream_readI_AB_I_I);
+
   jint ret =
     env->CallIntMethod(obj,
-      g_InputStream_readI_AB_I_I, p0, p1, p2);
+      method_id, p0, p1, p2);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InputStream_reset = 0;
+static base::subtle::AtomicWord g_InputStream_reset = 0;
 static void Java_InputStream_reset(JNIEnv* env, jobject obj) __attribute__
     ((unused));
 static void Java_InputStream_reset(JNIEnv* env, jobject obj) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_reset);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "reset",
+
+"("
+")"
+"V",
+      &g_InputStream_reset);
 
   env->CallVoidMethod(obj,
-      g_InputStream_reset);
+      method_id);
   base::android::CheckException(env);
 
 }
 
-static jmethodID g_InputStream_skip = 0;
+static base::subtle::AtomicWord g_InputStream_skip = 0;
 static jlong Java_InputStream_skip(JNIEnv* env, jobject obj, jlong p0)
     __attribute__ ((unused));
 static jlong Java_InputStream_skip(JNIEnv* env, jobject obj, jlong p0) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_skip);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "skip",
+
+"("
+"J"
+")"
+"J",
+      &g_InputStream_skip);
+
   jlong ret =
     env->CallLongMethod(obj,
-      g_InputStream_skip, p0);
+      method_id, p0);
   base::android::CheckException(env);
   return ret;
 }
 
-static jmethodID g_InputStream_Constructor = 0;
+static base::subtle::AtomicWord g_InputStream_Constructor = 0;
 static ScopedJavaLocalRef<jobject> Java_InputStream_Constructor(JNIEnv* env)
-__attribute__ ((unused));
+    __attribute__ ((unused));
 static ScopedJavaLocalRef<jobject> Java_InputStream_Constructor(JNIEnv* env) {
   /* Must call RegisterNativesImpl()  */
   DCHECK(g_InputStream_clazz);
-  DCHECK(g_InputStream_Constructor);
+  jmethodID method_id =
+  base::android::MethodID::LazyGet<
+      base::android::MethodID::TYPE_INSTANCE>(
+      env, g_InputStream_clazz,
+      "<init>",
+
+"("
+")"
+"V",
+      &g_InputStream_Constructor);
+
   jobject ret =
     env->NewObject(g_InputStream_clazz,
-      g_InputStream_Constructor);
+      method_id);
   base::android::CheckException(env);
   return ScopedJavaLocalRef<jobject>(env, ret);
 }
 
-// Step 3: GetMethodIDs and RegisterNatives.
-static void GetMethodIDsImpl(JNIEnv* env) {
-  g_InputStream_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
-      base::android::GetUnscopedClass(env, kInputStreamClassPath)));
-  g_InputStream_available =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "available",
-
-"("
-")"
-"I");
-
-  g_InputStream_close =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "close",
-
-"("
-")"
-"V");
-
-  g_InputStream_mark =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "mark",
-
-"("
-"I"
-")"
-"V");
-
-  g_InputStream_markSupported =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "markSupported",
-
-"("
-")"
-"Z");
-
-  g_InputStream_readI =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "read",
-
-"("
-")"
-"I");
-
-  g_InputStream_readI_AB =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "read",
-
-"("
-"[B"
-")"
-"I");
-
-  g_InputStream_readI_AB_I_I =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "read",
-
-"("
-"[B"
-"I"
-"I"
-")"
-"I");
-
-  g_InputStream_reset =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "reset",
-
-"("
-")"
-"V");
-
-  g_InputStream_skip =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "skip",
-
-"("
-"J"
-")"
-"J");
-
-  g_InputStream_Constructor =
-      base::android::GetMethodIDOrNull(
-          env, g_InputStream_clazz,
-          "<init>",
-
-"("
-")"
-"V");
-
-}
+// Step 3: RegisterNatives.
 
 static bool RegisterNativesImpl(JNIEnv* env) {
-  GetMethodIDsImpl(env);
 
+  g_InputStream_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kInputStreamClassPath)));
   return true;
 }
 }  // namespace JNI_InputStream