Remove duplicate symbols in .def for absl.dll

Bug: None
Change-Id: I89c105a652db701c083a03f1c0c891e00d2e6776
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2260754Reviewed-by: Mirko Bonadei <mbonadei@chromium.org>
Commit-Queue: Danil Chapovalov <danilchap@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781413}

third_party/abseil-cpp/BUILD.gn

@@ -35,20 +35,22 @@ component("absl") {
 
   public_deps = [
     "//third_party/abseil-cpp/absl/algorithm:container",
+    "//third_party/abseil-cpp/absl/base",
     "//third_party/abseil-cpp/absl/base:config",
     "//third_party/abseil-cpp/absl/base:core_headers",
     "//third_party/abseil-cpp/absl/container:inlined_vector",
-
-    # Disabled because of static initializers:
-    # "//third_party/abseil-cpp/absl/debugging:failure_signal_handler",
-    # "//third_party/abseil-cpp/absl/debugging:symbolize",
-
     "//third_party/abseil-cpp/absl/hash",
     "//third_party/abseil-cpp/absl/memory",
     "//third_party/abseil-cpp/absl/meta:type_traits",
+    "//third_party/abseil-cpp/absl/numeric:int128",
     "//third_party/abseil-cpp/absl/strings",
     "//third_party/abseil-cpp/absl/types:optional",
+    "//third_party/abseil-cpp/absl/types:span",
     "//third_party/abseil-cpp/absl/types:variant",
+
+    # Disabled because of static initializers:
+    # "//third_party/abseil-cpp/absl/debugging:failure_signal_handler",
+    # "//third_party/abseil-cpp/absl/debugging:symbolize",
   ]
 }
 

third_party/abseil-cpp/generate_def_file.py

@@ -56,13 +56,13 @@ def _GenerateDefFile(cpu):
 
     logging.info('[%s] Found %d object files.', cpu, len(obj_files))
 
-    absl_symbols = []
+    absl_symbols = set()
     for f in obj_files:
       stdout = subprocess.check_output(['llvm-nm-9', f], cwd=os.getcwd())
       for line in stdout.splitlines():
         match = re.match(ABSL_SYM_RE, line.decode('utf-8'))
         if match:
-          absl_symbols.append(match.group('symbol'))
+          absl_symbols.add(match.group('symbol'))
 
     logging.info('[%s] Found %d absl symbols.', cpu, len(absl_symbols))