Revert "Update codemirror to 5.27.2"

This reverts commit

* f5124487a4 (update to 5.27.2)
* 8edeb9e69c (update to 5.26.0)

Reason for revert: This breaks the GWTUI in the google deployment in mysterious ways:

gerrit_ui-0.js:65354 Thu Jun 29 13:36:57 GMT+200 2017 Class$S735 SEVERE: (TypeError) :
  Cannot read property 'attach' of undefined Class$S171: (TypeError) :
  Cannot read property 'attach' of undefined at Unknown.keyMap(https://gerrit-review.googlesource.com/gerrit_ui/5DADEBC80EFC7449BFD80840CBA4A5CF.cache.js)
    at Unknown.new CodeMirror$1(https://gerrit-review.googlesource.com/gerrit_ui/5DADEBC80EFC7449BFD80840CBA4A5CF.cache.js)
    at Unknown.CodeMirror$1(https://gerrit-review.googlesource.com/gerrit_ui/5DADEBC80EFC7449BFD80840CBA4A5CF.cache.js)
    at Unknown.newCM(gerrit_ui-7.js)
    at Unknown.create_73(gerrit_ui-7.js)
    at Unknown.newCm(gerrit_ui-2.js)

with the symptoms going away after a browser cache flush.

Our new library upgrade policy says that the upgrade window is already closed and this version does not provide any critical fixes.

Change-Id: I524608b6adf7f4276fc03ff9d8e91a779a9e9ae8

WORKSPACE

@@ -883,13 +883,13 @@ maven_jar(
 maven_jar(
     name = "codemirror_minified",
     artifact = "org.webjars.npm:codemirror-minified:" + CM_VERSION,
-    sha1 = "7464d1bf59a36b081981b855a51839bf3a1f302d",
+    sha1 = "f84c178b11a188f416b4380bfb2b24f126453d28",
 )
 
 maven_jar(
     name = "codemirror_original",
     artifact = "org.webjars.npm:codemirror:" + CM_VERSION,
-    sha1 = "8bcf4d541eba5c1c6916cb449fe4baf73d2ebd6f",
+    sha1 = "5a1f6c10d5aef0b9d2ce513dcc1e2657e4af730d",
 )
 
 maven_jar(

lib/codemirror/cm.bzl

@@ -214,7 +214,7 @@ CM_MODES = [
     "z80",
 ]
 
-CM_VERSION = "5.27.2"
+CM_VERSION = "5.25.0"
 
 TOP = "META-INF/resources/webjars/codemirror/%s" % CM_VERSION