Limit the number of files minizip_uncompress_fuzzer attempts to open.

If the input zip file contains too many files, it's possible for the
fuzzer to take too long to process every file. Cap the number of files
processed to keep fuzz time to a reasonable level.

BUG=933464

Change-Id: Icb01a4c4ca447aea1b1692a4cf4da92d1fe773cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1547540Reviewed-by: Oliver Chang <ochang@chromium.org>
Commit-Queue: Anand Mistry <amistry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#646679}

third_party/minizip/minizip_uncompress_fuzzer.cc

@@ -15,6 +15,7 @@ namespace {
 const char kTestPassword[] = "test123";
 const char kTestFileName[] = "foo";
 const char kTestFileNameUppercase[] = "FOO";
+const int kMaxFiles = 128;
 }
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
@@ -37,7 +38,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     mz_zip_get_number_entry(zip_file, &num_entries);
 
     result = mz_zip_goto_first_entry(zip_file);
-    while (result == MZ_OK) {
+    for (int i = 0; result == MZ_OK && i < kMaxFiles; i++) {
       mz_zip_file* file_info = nullptr;
       result = mz_zip_entry_get_info(zip_file, &file_info);
       if (result != MZ_OK) {