Update from https://crrev.com/333737

base/android/linker/linker_jni.cc

Index: base/android/linker/linker_jni.cc
diff --git a/base/android/linker/linker_jni.cc b/base/android/linker/linker_jni.cc
index b79eaf43bc156dd16efc2b3c21f752e6be097796..2bc480cf776dd6af931cd9885c1f6c2287adc2fd 100644
--- a/base/android/linker/linker_jni.cc
+++ b/base/android/linker/linker_jni.cc
@@ -447,17 +447,6 @@ jboolean LoadLibraryInZipFile(JNIEnv* env,
       static_cast<size_t>(load_address), lib_info_obj, opener);
 }
 
-// Enable the fallback due to lack of support for mapping the APK file with
-// executable permission in the crazy linker.
-//
-// |env| is the current JNI environment handle and is ignored here.
-// |clazz| is the static class handle for org.chromium.base.Linker,
-// and is ignored here.
-void EnableNoMapExecSupportFallback(JNIEnv* env, jclass clazz) {
-  crazy_context_t* context = GetCrazyContext();
-  crazy_context_set_no_map_exec_support_fallback_enabled(context, true);
-}
-
 // Class holding the Java class and method ID for the Java side Linker
 // postCallbackOnMainThread method.
 struct JavaCallbackBindings_class {
@@ -670,42 +659,6 @@ jstring GetLibraryFilePathInZipFile(JNIEnv* env,
   return env->NewStringUTF(buffer);
 }
 
-// Check whether the device supports mapping the APK file with executable
-// permission.
-//
-// |env| is the current JNI environment handle.
-// |clazz| is the static class handle which is not used here.
-// |apkfile_name| is the filename of the APK.
-// Returns true if supported.
-jboolean CheckMapExecSupport(JNIEnv* env, jclass clazz, jstring apkfile_name) {
-  String apkfile_name_str(env, apkfile_name);
-  const char* apkfile_name_c_str = apkfile_name_str.c_str();
-
-  int fd = open(apkfile_name_c_str, O_RDONLY);
-  if (fd == -1) {
-    LOG_ERROR("%s: Failed to open %s\n", __FUNCTION__, apkfile_name_c_str);
-    return false;
-  }
-
-  LOG_INFO(
-      "%s: Memory mapping the first page of %s with executable permissions\n",
-      __FUNCTION__, apkfile_name_c_str);
-  void* address = mmap(NULL, PAGE_SIZE, PROT_EXEC, MAP_PRIVATE, fd, 0);
-
-  jboolean status;
-  if (address == MAP_FAILED) {
-    status = false;
-  } else {
-    status = true;
-    munmap(address, PAGE_SIZE);
-  }
-
-  close(fd);
-
-  LOG_INFO("%s: %s\n", __FUNCTION__, status ? "Supported" : "NOT supported");
-  return status;
-}
-
 // Check whether a library is page aligned and uncompressed in the APK file.
 //
 // |env| is the current JNI environment handle.
@@ -748,11 +701,6 @@ const JNINativeMethod kNativeMethods[] = {
      ")"
      "Z",
      reinterpret_cast<void*>(&LoadLibraryInZipFile)},
-    {"nativeEnableNoMapExecSupportFallback",
-     "("
-     ")"
-     "V",
-     reinterpret_cast<void*>(&EnableNoMapExecSupportFallback)},
     {"nativeRunCallbackOnUiThread",
      "("
      "J"
@@ -791,12 +739,6 @@ const JNINativeMethod kNativeMethods[] = {
      ")"
      "Ljava/lang/String;",
      reinterpret_cast<void*>(&GetLibraryFilePathInZipFile)},
-    {"nativeCheckMapExecSupport",
-     "("
-     "Ljava/lang/String;"
-     ")"
-     "Z",
-     reinterpret_cast<void*>(&CheckMapExecSupport)},
     {"nativeCheckLibraryIsMappableInApk",
      "("
      "Ljava/lang/String;"