New Additions

• Add instance method alises on goog.structs.StringSet to align it with ES6 Set. (ee36b88ec775b91b1ca47b9f7f8be62a16fb6686)
• Removes references to goog\.structs\.Map in WebChannel code. (74ae512c6c08f21472db8ea6eb9bffd02469289d)

Backwards Incompatible Changes

• Make ModuleManager handle when "synthetic" modules dont mark themselves as loaded (e19c97b19fd1effc9c17a930145e8f75f9f0b769)
• Type definition for goog.i18n.NumberFormatSymbols changed. (cfab9e26187683a9eb19060091fda89a01eb4958)
• goog.log.LogRecord.getException now returns * and defaults to undefined. setException and other APIs have been adjusted accordingly. (c244e80d2e0ada44d16524f9600dc14e5364f2da)
• Tests that override shouldRunTests will now cache the result of the first time shouldRunTests is executed. Tests that may have been incorrectly skipped will now start running. (645d11a6bd4ba5dac5b49dce312fcbc89a927672)
• setModuleConstructor now explicitly requires a parameter-less (4bb0dca767881169f7d16f8c743585f0dbbd8e6c)

Other Changes

• Fix Date.add behavior for years 0-99. (4ad6ca7ff623190bbe5aa2fd4863be0f1de7c89c)
• Get userAgent browser info from userAgentData whenever possible. (619f3fcc5ba40a1f8c5a37bd9dd94aaffee01841)
• Add HTTP 499 to goog.net.HttpStatus* packages (b3a823e8f04431c0d7e5907e8dbdc6f2622284e9)
• Added goog.math.Long.hashCode function that returns 32 bit hash code of the long. (1f3f3d06a3aaf8a551aadee57464311e0e9e9d5d)
• Publish BUILD files with closure-library. (cfbdb31c1c3971634fb215744891035c246a1522)
• Use closure_base_js_library for closure:base and setup WORKSPACE for bazel repo. (73debba8c8d74f26acfc8f7b9770617420a0dd57)
• Formatting uses ECMASCript Intl class in modern browsers. (51d4398c3b67bc5dccc649e009be2439524ac703)
• Use Client hints API to get device isMobile info. (cb82c4773473bbc29e2a0c0702aa15f266452021)
• Support addEventListener in pixeldensitymonitor. (e12df7e76ef9cee63ccfb45a0d13febaa01ad3d7)
• Avoids setting unknown fields with null value when used along with pbliteserializer. (8eb6cbe0ac2a6cfb9d6c6676be30f71b78823b31)