Make unique id counter a member of TSymbolTable

This makes unique id counting thread-safe.

BUG=angleproject:624
TEST=angle_unittests

Change-Id: Ie0f2c7e574470b39750d37d2181c790bc874b275
Reviewed-on: https://chromium-review.googlesource.com/570419
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/ValidateLimitations.cpp b/src/compiler/translator/ValidateLimitations.cpp
index 10e57f5..941f79a 100644
--- a/src/compiler/translator/ValidateLimitations.cpp
+++ b/src/compiler/translator/ValidateLimitations.cpp
@@ -71,7 +71,7 @@
 {
   public:
     ValidateLimitationsTraverser(sh::GLenum shaderType,
-                                 const TSymbolTable &symbolTable,
+                                 TSymbolTable *symbolTable,
                                  int shaderVersion,
                                  TDiagnostics *diagnostics);
 
@@ -104,7 +104,7 @@
 };
 
 ValidateLimitationsTraverser::ValidateLimitationsTraverser(sh::GLenum shaderType,
-                                                           const TSymbolTable &symbolTable,
+                                                           TSymbolTable *symbolTable,
                                                            int shaderVersion,
                                                            TDiagnostics *diagnostics)
     : TLValueTrackingTraverser(true, false, false, symbolTable, shaderVersion),
@@ -432,7 +432,7 @@
 
 bool ValidateLimitations(TIntermNode *root,
                          GLenum shaderType,
-                         const TSymbolTable &symbolTable,
+                         TSymbolTable *symbolTable,
                          int shaderVersion,
                          TDiagnostics *diagnostics)
 {