[libfuzzer] proto-based renderer fuzzer draft

content/test/fuzzer/BUILD.gn

Index: content/test/fuzzer/BUILD.gn
diff --git a/content/test/fuzzer/BUILD.gn b/content/test/fuzzer/BUILD.gn
index 4222577ca615d7b6ba2a162d78ff99c4e586a563..e4459eda4d4b66911518de89ba37dc2cc1ed513e 100644
--- a/content/test/fuzzer/BUILD.gn
+++ b/content/test/fuzzer/BUILD.gn
@@ -5,6 +5,7 @@
 # Fuzzers for content/ components.
 
 import("//testing/libfuzzer/fuzzer_test.gni")
+import("//third_party/protobuf/proto_library.gni")
 
 # Empty group for package discovery.
 group("fuzzer") {
@@ -67,4 +68,22 @@ if (!is_component_build) {
     ]
     seed_corpus = "//content/test/data/fuzzer_corpus/clear_site_data/"
   }
+
+  fuzzer_test("renderer_proto_tree_fuzzer") {
+    sources = [
+      "renderer_proto_tree_fuzzer.cc",
+    ]
+    deps = [
+      ":fuzzer_support",
+      ":html_tree_proto",
+      "//third_party/libprotobuf-mutator",
+    ]
+  }
+
+  proto_library("html_tree_proto") {
+    sources = [
+      "html_tree.proto",
+    ]
+    testonly = true
+  }
 }