[LayoutlibLoader] Print exception when FindClassOrDie, etc fail

Bug: 318393625
Test: Manual test with an unloadable class
Change-Id: Ifc7dca37f858cc1f76fcbfe6fc8c1bfbe75ab10a
diff --git a/core/jni/LayoutlibLoader.cpp b/core/jni/LayoutlibLoader.cpp
index 01e9f43..06d5eb3 100644
--- a/core/jni/LayoutlibLoader.cpp
+++ b/core/jni/LayoutlibLoader.cpp
@@ -362,6 +362,22 @@
 
 using namespace android;
 
+// Called right before aborting by LOG_ALWAYS_FATAL. Print the pending exception.
+void abort_handler(const char* abort_message) {
+    ALOGE("Abort to abort the process...");
+
+    JNIEnv* env = NULL;
+    if (javaVM->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
+        ALOGE("vm->GetEnv() failed");
+        return;
+    }
+    if (env->ExceptionOccurred() != NULL) {
+        ALOGE("Pending exception:");
+        env->ExceptionDescribe();
+    }
+    ALOGE("Aborting because: %s", abort_message);
+}
+
 JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void*) {
     javaVM = vm;
     JNIEnv* env = nullptr;
@@ -369,6 +385,8 @@
         return JNI_ERR;
     }
 
+    __android_log_set_aborter(abort_handler);
+
     init_android_graphics();
 
     // Configuration is stored as java System properties.