Update import order CheckStyle configuration.

The import order now separates Chromium (and downstream) imports from other
imports with com or org prefixes.

Also remove some prefixes that aren't used in Chromium code.

Finally, add an importorder file for configuring the import order in Eclipse.

Review-Url: https://codereview.chromium.org/2052823002
Cr-Commit-Position: refs/heads/master@{#422818}

tools/android/checkstyle/chromium-style-5.0.xml

@@ -166,8 +166,8 @@
     </module>
     <module name="ImportOrder">
       <property name="severity" value="error"/>
-      <message key="import.ordering" value="Wrong order for {0} import. Use :JavaImportOrganize (ECLIM) or Ctrl+Shift+O (Eclipse) to sort imports"/>
-      <property name="groups" value="android, com, dalvik, gov, junit, libcore, net, org, java, javax"/>
+      <message key="import.ordering" value="Wrong order for {0} import. Use :JavaImportOrganize (ECLIM) or Ctrl+Shift+O (Eclipse) to sort imports. An importorder file for configuring Eclipse can be found at //tools/android/eclipse/android.importorder."/>
+      <property name="groups" value="android, com, dalvik, junit, org, com.google.android.apps.chrome, org.chromium, java, javax"/>
       <property name="ordered" value="true"/>
       <property name="option" value="top"/>
       <property name="separated" value="true"/>

tools/android/eclipse/android.importorder

+8=javax
+7=java
+6=org.chromium
+5=com.google.android.apps.chrome
+4=org
+3=junit
+2=dalvik
+1=com
+0=android