Android: Switch ContentShell to use implicit JNI registration

Explicit registration is needed only when using the custom linker.
Content shell doesn't use the custom linker, so has no need to jump
through the extra hoops involved with explicit registration.

Change motivated by JNI refactorings, which are made simpler by having
fewer targets use manual JNI registration.

Bug: 898261
Change-Id: Ia38529c1df92264781ba64235a7aea749ef0356a
Reviewed-on: https://chromium-review.googlesource.com/c/1317338Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605344}

content/shell/android/BUILD.gn

@@ -19,18 +19,10 @@ generate_jni("content_shell_jni_headers") {
   ]
 }
 
-generate_jni_registration("content_shell_jni_registration") {
-  testonly = true
-  target = ":content_shell_apk"
-  output = "$root_gen_dir/content/shell/android/${target_name}.h"
-  exception_files = jni_exception_files
-}
-
 shared_library("libcontent_shell_content_view") {
   testonly = true
   deps = [
     ":content_shell_jni_headers",
-    ":content_shell_jni_registration",
     "//components/crash/content/browser",
     "//content/shell:content_shell_lib",
     "//content/shell:pak",
@@ -49,12 +41,13 @@ shared_library("libcontent_shell_content_view") {
   sources = [
     "shell_library_loader.cc",
   ]
+  configs -= [ "//build/config/android:hide_all_but_jni_onload" ]
+  configs += [ "//build/config/android:hide_all_but_jni" ]
 }
 
 shared_library("libcontent_native_test") {
   testonly = true
   deps = [
-    ":content_test_jni_registration",
     "//base",
     "//content/public/test/android:content_native_test_support",
     "//content/shell:content_shell_lib",
@@ -63,6 +56,8 @@ shared_library("libcontent_native_test") {
   sources = [
     "shell_test_library_loader.cc",
   ]
+  configs -= [ "//build/config/android:hide_all_but_jni_onload" ]
+  configs += [ "//build/config/android:hide_all_but_jni" ]
 }
 
 android_resources("content_shell_java_resources") {
@@ -216,13 +211,6 @@ android_library("content_shell_test_java") {
   ]
 }
 
-generate_jni_registration("content_test_jni_registration") {
-  testonly = true
-  target = ":content_shell_test_apk__apk"
-  output = "$root_gen_dir/content/shell/android/${target_name}.h"
-  exception_files = jni_exception_files
-}
-
 instrumentation_test_apk("content_shell_test_apk") {
   deps = [
     "//base:base_java_test_support",

content/shell/android/shell_library_loader.cc

@@ -3,27 +3,15 @@
 // found in the LICENSE file.
 
 #include "base/android/jni_android.h"
-#include "base/android/jni_utils.h"
-#include "base/android/library_loader/library_loader_hooks.h"
-#include "base/bind.h"
 #include "content/public/app/content_jni_onload.h"
 #include "content/public/app/content_main.h"
 #include "content/public/browser/android/compositor.h"
-#include "content/shell/android/content_shell_jni_registration.h"
 #include "content/shell/app/shell_main_delegate.h"
 
 // This is called by the VM when the shared library is first loaded.
 JNI_EXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
   base::android::InitVM(vm);
-  JNIEnv* env = base::android::AttachCurrentThread();
-  if (!RegisterMainDexNatives(env))
-    return -1;
 
-  // Do not register JNI methods in secondary dex for non-browser process.
-  bool is_browser_process =
-      !base::android::IsSelectiveJniRegistrationEnabled(env);
-  if (is_browser_process && !RegisterNonMainDexNatives(env))
-    return -1;
   if (!content::android::OnJNIOnLoadInit())
     return -1;
 

content/shell/android/shell_test_library_loader.cc

@@ -3,26 +3,14 @@
 // found in the LICENSE file.
 
 #include "base/android/jni_android.h"
-#include "base/android/jni_utils.h"
 #include "content/public/app/content_jni_onload.h"
 #include "content/public/app/content_main.h"
 #include "content/public/browser/android/compositor.h"
-#include "content/shell/android/content_test_jni_registration.h"
 #include "content/shell/app/shell_main_delegate.h"
 
 // This is called by the VM when the shared library is first loaded.
 JNI_EXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
   base::android::InitVM(vm);
-  JNIEnv* env = base::android::AttachCurrentThread();
-  if (!base::android::IsSelectiveJniRegistrationEnabled(env)) {
-    if (!RegisterNonMainDexNatives(env)) {
-      return -1;
-    }
-  }
-
-  if (!RegisterMainDexNatives(env)) {
-    return -1;
-  }
   if (!content::android::OnJNIOnLoadInit())
     return -1;
   content::Compositor::Initialize();