Make fields readonly

src/Compilers/Core/Portable/InternalUtilities/FatalError.cs

@@ -173,7 +173,7 @@ public static bool ReportWithoutCrashUnlessCanceledAndPropagate(Exception except
             return false;
         }
 
-        private static object s_reportedMarker = new object();
+        private static readonly object s_reportedMarker = new object();
 
         private static void Report(Exception exception, Action<Exception> handler)
         {

src/VisualStudio/Core/SolutionExplorerShim/AnalyzerItem/AnalyzerItem.BrowseObject.cs

@@ -9,7 +9,7 @@ internal partial class AnalyzerItem
     {
         internal class BrowseObject : LocalizableProperties
         {
-            private AnalyzerItem _analyzerItem;
+            private readonly AnalyzerItem _analyzerItem;
 
             public BrowseObject(AnalyzerItem analyzerItem)
             {

src/VisualStudio/Core/SolutionExplorerShim/AnalyzerItem/AnalyzerItemProvider.cs

@@ -13,7 +13,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Implementation.SolutionExplore
     internal sealed class AnalyzerItemProvider : AttachedCollectionSourceProvider<AnalyzersFolderItem>
     {
         [Import(typeof(AnalyzersCommandHandler))]
-        private IAnalyzersCommandHandler _commandHandler = null;
+        private readonly IAnalyzersCommandHandler _commandHandler = null;
 
         [ImportingConstructor]
         public AnalyzerItemProvider()

src/VisualStudio/Core/SolutionExplorerShim/AnalyzerItemTracker.cs

@@ -17,7 +17,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Implementation.SolutionExplore
     [Export]
     internal class AnalyzerItemsTracker : IVsSelectionEvents
     {
-        private IServiceProvider _serviceProvider;
+        private readonly IServiceProvider _serviceProvider;
         private IVsMonitorSelection _vsMonitorSelection = null;
         private uint _selectionEventsCookie = 0;
 

src/VisualStudio/Core/SolutionExplorerShim/AnalyzerReferenceManager.cs

@@ -22,7 +22,7 @@ internal class AnalyzerReferenceManager : IVsReferenceManagerUser
         private IVsReferenceManager _referenceManager;
 
         [Import]
-        private AnalyzerItemsTracker _tracker = null;
+        private readonly AnalyzerItemsTracker _tracker = null;
 
         [ImportingConstructor]
         public AnalyzerReferenceManager(

src/VisualStudio/Core/SolutionExplorerShim/BrowseObjectAttributes.cs

@@ -13,7 +13,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Implementation.SolutionExplore
     [AttributeUsage(AttributeTargets.Property)]
     internal sealed class BrowseObjectDisplayNameAttribute : DisplayNameAttribute
     {
-        private string m_key;
+        private readonly string m_key;
         private bool m_initialized;
 
         public BrowseObjectDisplayNameAttribute(string key)

src/VisualStudio/Core/SolutionExplorerShim/DiagnosticItem/BaseDiagnosticItem.BrowseObject.cs

@@ -13,7 +13,7 @@ internal abstract partial class BaseDiagnosticItem
     {
         internal class BrowseObject : LocalizableProperties
         {
-            private BaseDiagnosticItem _diagnosticItem;
+            private readonly BaseDiagnosticItem _diagnosticItem;
 
             public BrowseObject(BaseDiagnosticItem diagnosticItem)
             {