IWYU: Include all headers for symbols used in files.

Semi-automatically taking the the misc-include-cleaner warnings
by clang-tidy and fixing files to be self-contained.

Change-Id: Iaaa2b2ec9d6dcce547fa5cb6b4f056dfc8c781ff

tests/fuzzer/imageio_fuzzer.cc

@@ -34,7 +34,7 @@ void TestReader(const uint8_t *data, size_t size, WebPImageReader reader,
   WebPPicture pic;
   if (!WebPPictureInit(&pic)) {
     std::cerr << "WebPPictureInit failed" << std::endl;
-    abort();
+    std::abort();
   }
   Metadata metadata;
   MetadataInit(&metadata);