Remove some dead code from CFX_CSSSyntaxParser

The kUnknownRule case can never be hit because there are no paths
that set m_eMode to kUnknownRule. Additionally, a stray close brace
while looking for a ruleset is always an error since we don't support
recursive braces anyways (such as might have been introduced with
at-rules or the like).


Change-Id: I52d89099bf9bc4d6559c1241ada507dc466ce3a5
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/66512
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxcrt/css/cfx_csssyntaxparser.cpp b/core/fxcrt/css/cfx_csssyntaxparser.cpp
index 6b05b3f..2524a38 100644
--- a/core/fxcrt/css/cfx_csssyntaxparser.cpp
+++ b/core/fxcrt/css/cfx_csssyntaxparser.cpp
@@ -47,9 +47,6 @@
       case SyntaxMode::kRuleSet:
         switch (wch) {
           case '}':
-            m_Input.MoveNext();
-            if (RestoreMode())
-              return CFX_CSSSyntaxStatus::kDeclClose;
             m_bError = true;
             return CFX_CSSSyntaxStatus::kError;
           case '/':
@@ -156,11 +153,6 @@
         }
         m_Input.MoveNext();
         break;
-      case SyntaxMode::kUnknownRule:
-        if (wch == ';')
-          SwitchMode(SyntaxMode::kRuleSet);
-        m_Input.MoveNext();
-        break;
       default:
         NOTREACHED();
         break;
diff --git a/core/fxcrt/css/cfx_csssyntaxparser.h b/core/fxcrt/css/cfx_csssyntaxparser.h
index ba64add..53630cf 100644
--- a/core/fxcrt/css/cfx_csssyntaxparser.h
+++ b/core/fxcrt/css/cfx_csssyntaxparser.h
@@ -41,7 +41,6 @@
   enum class SyntaxMode : uint8_t {
     kRuleSet,
     kComment,
-    kUnknownRule,
     kSelector,
     kPropertyName,
     kPropertyValue,