Remove Windows-related GN build configuration

build/sanitizers/BUILD.gn

Index: build/sanitizers/BUILD.gn
diff --git a/build/sanitizers/BUILD.gn b/build/sanitizers/BUILD.gn
index 4f81f3ebadd0b5071c2dce7322af16251c1739bc..c4afd024e6d355c32b371339869b9789a381e4e1 100644
--- a/build/sanitizers/BUILD.gn
+++ b/build/sanitizers/BUILD.gn
@@ -5,20 +5,11 @@
 if (is_linux && !is_chromeos) {
   # TODO(GYP): Figure out which of these work and are needed on other platforms.
   copy("copy_llvm_symbolizer") {
-    if (is_win) {
-      sources = [
-        "//third_party/llvm-build/Release+Asserts/bin/llvm-symbolizer.exe",
-      ]
-      outputs = [
-        "$root_out_dir/llvm-symbolizer.exe",
-      ]
-    } else {
-      sources = [
-        "//third_party/llvm-build/Release+Asserts/bin/llvm-symbolizer",
-      ]
-      outputs = [
-        "$root_out_dir/llvm-symbolizer",
-      ]
-    }
+    sources = [
+      "//third_party/llvm-build/Release+Asserts/bin/llvm-symbolizer",
+    ]
+    outputs = [
+      "$root_out_dir/llvm-symbolizer",
+    ]
   }
 }