Warn if using Open JDK.

Open JDK users continue to report intermittent performance issues such
as the IDE coming to a crawl after use for longer periods of time.

Change-Id: I28088a938e500d39e57182dd52f3413300478da7
(cherry picked from commit ac56866420dbdaaef953828c332ef88876d34c56)
diff --git a/platform/platform-impl/src/com/intellij/ide/SystemHealthMonitor.java b/platform/platform-impl/src/com/intellij/ide/SystemHealthMonitor.java
index f8c4e3c..29ad33b 100644
--- a/platform/platform-impl/src/com/intellij/ide/SystemHealthMonitor.java
+++ b/platform/platform-impl/src/com/intellij/ide/SystemHealthMonitor.java
@@ -66,7 +66,7 @@
   }
 
   private void checkJvm() {
-    if (StringUtil.containsIgnoreCase(System.getProperty("java.vm.name", ""), "OpenJDK") && !SystemInfo.isJavaVersionAtLeast("1.7")) {
+    if (StringUtil.containsIgnoreCase(System.getProperty("java.vm.name", ""), "OpenJDK")) {
       notifyUnsupportedJvm("unsupported.jvm.openjdk.message");
     }
     else if (StringUtil.endsWithIgnoreCase(System.getProperty("java.version", ""), "-ea")) {
diff --git a/platform/platform-resources-en/src/messages/IdeBundle.properties b/platform/platform-resources-en/src/messages/IdeBundle.properties
index af07531..5ca152b 100644
--- a/platform/platform-resources-en/src/messages/IdeBundle.properties
+++ b/platform/platform-resources-en/src/messages/IdeBundle.properties
@@ -1097,7 +1097,7 @@
 browsers.settings=Web Browsers
 updates.check.period.on.exit=On every exit
 
-unsupported.jvm.openjdk.message=OpenJDK 6 is not supported. Please use Oracle Java or newer OpenJDK.
+unsupported.jvm.openjdk.message=OpenJDK shows intermittent performance and UI issues. We recommend using the Oracle JRE/JDK.
 unsupported.jvm.ea.message=Early Access Java versions may cause compatibility issues. Please use stable release.
 unsupported.jvm.link=<br/><a href="#">Do not show again</a>.