Fix eclipse .classpath for Android API 28 migration.

BUG=

Change-Id: I79be463e073aff1c6def72032fd362dd3b83f66d
Reviewed-on: https://chromium-review.googlesource.com/1118763Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571189}

tools/android/eclipse/.classpath

@@ -229,7 +229,7 @@ to the classpath for downstream development. See "additional_entries" below.
     <classpathentry kind="src" path="out/Debug/remoting_apk/gen"/>
     <classpathentry kind="src" path="out/Debug/webview_instrumentation_test_apk/gen"/>
     <classpathentry kind="lib" path="third_party/android_tools/sdk/extras/google/gcm/gcm-client/dist/gcm.jar" sourcepath="third_party/android_tools/sdk/extras/google/gcm/gcm-client/src"/>
-    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-27/android.jar" sourcepath="third_party/android_tools/sdk/sources/">
+    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-28/android.jar" sourcepath="third_party/android_tools/sdk/sources/">
         <attributes>
             <attribute name="javadoc_location" value="http://developer.android.com/reference/"/>
         </attributes>