Fix import of chromium into webrtc.

Chromium jni generator was updated, so we need to sync our header with
chromium one, which located here:
https://cs.chromium.org/chromium/src/base/android/jni_generator/jni_generator_helper.h

Generator was updated in CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1296827

BUG=NONE

Change-Id: Ib07f86d2e5490467771aa7d5e4eb5d8f7075e16e
Reviewed-on: https://webrtc-review.googlesource.com/c/108340
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25414}

sdk/android/src/jni/jni_generator_helper.h

@@ -33,12 +33,6 @@
   RTC_CHECK(!jni->ExceptionCheck()) \
       << (jni->ExceptionDescribe(), jni->ExceptionClear(), "")
 
-namespace jni_generator {
-inline void CheckException(JNIEnv* env) {
-  CHECK_EXCEPTION(env);
-}
-}  // namespace jni_generator
-
 namespace webrtc {
 
 // This function will initialize |atomic_class_id| to contain a global ref to
@@ -86,4 +80,80 @@ using webrtc::MethodID;
 }  // namespace android
 }  // namespace base
 
+namespace jni_generator {
+inline void CheckException(JNIEnv* env) {
+  CHECK_EXCEPTION(env);
+}
+
+// A 32 bit number could be an address on stack. Random 64 bit marker on the
+// stack is much less likely to be present on stack.
+constexpr uint64_t kJniStackMarkerValue = 0xbdbdef1bebcade1b;
+
+// Context about the JNI call with exception checked to be stored in stack.
+struct BASE_EXPORT JniJavaCallContextUnchecked {
+  inline JniJavaCallContextUnchecked() {
+// TODO(ssid): Implement for other architectures.
+#if defined(__arm__) || defined(__aarch64__)
+    // This assumes that this method does not increment the stack pointer.
+    asm volatile("mov %0, sp" : "=r"(sp));
+#else
+    sp = 0;
+#endif
+  }
+
+  // Force no inline to reduce code size.
+  template <base::android::MethodID::Type type>
+  void Init(JNIEnv* env,
+            jclass clazz,
+            const char* method_name,
+            const char* jni_signature,
+            std::atomic<jmethodID>* atomic_method_id) {
+    env1 = env;
+
+    // Make sure compiler doesn't optimize out the assignment.
+    memcpy(&marker, &kJniStackMarkerValue, sizeof(kJniStackMarkerValue));
+    // Gets PC of the calling function.
+    pc = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
+
+    method_id = base::android::MethodID::LazyGet<type>(
+        env, clazz, method_name, jni_signature, atomic_method_id);
+  }
+
+  ~JniJavaCallContextUnchecked() {
+    // Reset so that spurious marker finds are avoided.
+    memset(&marker, 0, sizeof(marker));
+  }
+
+  uint64_t marker;
+  uintptr_t sp;
+  uintptr_t pc;
+
+  JNIEnv* env1;
+  jmethodID method_id;
+};
+
+// Context about the JNI call with exception unchecked to be stored in stack.
+struct BASE_EXPORT JniJavaCallContextChecked {
+  // Force no inline to reduce code size.
+  template <base::android::MethodID::Type type>
+  void Init(JNIEnv* env,
+            jclass clazz,
+            const char* method_name,
+            const char* jni_signature,
+            std::atomic<jmethodID>* atomic_method_id) {
+    base.Init<type>(env, clazz, method_name, jni_signature, atomic_method_id);
+    // Reset |pc| to correct caller.
+    base.pc = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
+  }
+
+  ~JniJavaCallContextChecked() { jni_generator::CheckException(base.env1); }
+
+  JniJavaCallContextUnchecked base;
+};
+
+static_assert(sizeof(JniJavaCallContextChecked) ==
+                  sizeof(JniJavaCallContextUnchecked),
+              "Stack unwinder cannot work with structs of different sizes.");
+}  // namespace jni_generator
+
 #endif  // SDK_ANDROID_SRC_JNI_JNI_GENERATOR_HELPER_H_