New Additions

• DebugError constructor takes an optional error as a cause for error chaining. (8797fa82e0f1c061e64f04de3c203ab13ae43e1c)
• Implement a predictive parsing option for goog.i18n.DateTimeParse with support for limited pattern symbols. (1e6e512f7ef895f8d3b064a8c682dc5342aec1da)

Backwards Incompatible Changes

• Delete an unused goog.provide goog.fx.TransitionBase.State. (5ee9c7f1ee0090017f813b9e6516d4fa0fc2d0fd)
• Some private-looking constants (TRANSPORT_SERVICE_ and SETUP_ACK_) that were actually being used outside of goog.net.xpc have been renamed and locked down to @package-visible. (3688e9a30a47075adcb2e1536604205216d41be3)
• Removed goog.ui.media.FlashObject (396116741bc0fb5c7302a044d4d2e2f39bf34e9e)
• Remove goog.html.flash (c5f6e8e99b3f2269e8409b03da63ba3d2c751406)
• Drops support for legacy browsers (IE<=8) in OnlineHandler (cae5f13a9a243ef48154eba48f381beaef66d74a)

Other Changes

• Capture the Native URL constructor on module load to avoid it being clobbered by users. (18edb20547fc42345c96edf9fd2c225fdab631a3)
• Remove flash reference from userAgent demo (131b2f82ffce531cac21be56b72bd2053751ad40)
• Expose LoadOptions type for AbstractModuleLoader (306254f23500721bd792260aeee412ff98a3ea4e)
• debug.normalizeErrorObject() returns a consistent object across browsers. (fbbe58aeaef8096bb131d7bc08684424b52c8381)
• Remove optional parameter to hasNativeComparator, and use goog.FEATURESET_YEAR. (9106b74a86994c751192b351a2f9da191bdee8e0)
• Add goog.dom.safe.getStyleNonce. (634c79e686948739cb1c6b5fd69590897e845d25)
• Removed goog.userAgent.flash (f62aba053918937f39d38fa51135a74555ad5edf)
• Use ECMAScript Intl object when supported by browsers for relative date time formatting. (ef3fcb3ddf3bfc3c1de33ef3fdcef40553b1198c)
• Use paddingTop instead of paddingBottom to nudge textarea element. (914e6ad8a42d131d6db705c4cd133a1e9b47ce71)
• The ability to detect Content Security Policy (CSP) violations during unit tests has been added to the Closure testing framework. (7968899bc26b88d7658e305178c3b5505bb3de36)
• Add nonce in goog.dom.safe.setLinkHrefAndRel. We already do this goog.style.installSafeStyleSheet. (6c84afcb5ffc194d918deafcbfa190095c5ac541)
• If a shortcut that conflicts with an existing one is registered, have the triggered error show the existing shortcut that would be overridden. (40a889f18208591bd0d87112f6e0b9a89235d9a7)