[Build Tasks] Add LogErrorForXmlNode (#209)

Adds a copy of LogWarningForXmlNode that logs an error instead of a
warning.

Author: pjcollins

src/Microsoft.Android.Build.BaseTasks/MSBuildExtensions.cs

@@ -135,6 +135,33 @@ public static void LogCodedWarning (this TaskLoggingHelper log, string code, str
 log.LogWarning(string.Empty,code,string.Empty,file,lineNumber,0,0,0,message,messageArgs);
 }
 
+/// <summary>
+/// Logs a coded error from a node in an XML document
+/// </summary>
+/// <param name="node">An element that implements IXmlLineInfo</param>
+publicstaticvoidLogErrorForXmlNode(thisTaskLoggingHelperlog,stringcode,stringfile,objectnode,stringmessage,paramsobject[]messageArgs)
+{
+intlineNumber=0;
+intcolumnNumber=0;
+varlineInfo=nodeasIXmlLineInfo;
+if(lineInfo!=null&&lineInfo.HasLineInfo()){
+lineNumber=lineInfo.LineNumber;
+columnNumber=lineInfo.LinePosition;
+}
+log.LogError(
+subcategory:string.Empty,
+errorCode:code,
+helpKeyword:string.Empty,
+file:file,
+lineNumber:lineNumber,
+columnNumber:columnNumber,
+endLineNumber:0,
+endColumnNumber:0,
+message:message,
+messageArgs:messageArgs
+);
+}
+
 /// <summary>
 /// Logs a coded warning from a node in an XML document
 /// </summary>