Issue 23640. Implement 'analysis.getNavigation' request.

pkg/analysis_server/tool/spec/spec_input.html

Index: pkg/analysis_server/tool/spec/spec_input.html
diff --git a/pkg/analysis_server/tool/spec/spec_input.html b/pkg/analysis_server/tool/spec/spec_input.html
index 6347f46f4c3154a4990245ac4b5927711ea3aee1..994dd4905f0bf13343b0ee8093d84f877f694f42 100644
--- a/pkg/analysis_server/tool/spec/spec_input.html
+++ b/pkg/analysis_server/tool/spec/spec_input.html
@@ -441,6 +441,13 @@
           always choosing a region that starts at the beginning of a line and
           ends at the end of a (possibly different) line in the file.
         </p>
+        <p>
+          If a request is made for a file which does not exist, or
+          which is not currently subject to analysis (e.g. because it
+          is not associated with any analysis root specified to
+          analysis.setAnalysisRoots), an error of type
+          <tt>GET_NAVIGATION_INVALID_FILE</tt> will be generated.
+        </p>
         <params>
           <field name="file">
             <ref>FilePath</ref>
@@ -3181,6 +3188,14 @@
             </p>
           </value>
           <value>
+            <code>GET_NAVIGATION_INVALID_FILE</code>
+            <p>
+              An "analysis.getErrors" request specified a FilePath

[devoncarew, 2015/07/14 16:34:35]

DBC: This looks like a copy/paste issue - this should probably say
"analysis.getNavigation".

[scheglov, 2015/07/21 15:05:53]

Thanks!
https://codereview.chromium.org/1243073004

+              which does not match a file currently subject to
+              analysis.
+            </p>
+          </value>
+          <value>
             <code>INVALID_ANALYSIS_ROOT</code>
             <p>
               A path passed as an argument to a request (such as