[Merge to XFA] Revert "Revert "Add type cast definitions for CPDF_Dictionary.""

core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp

Index: core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
index 2d6e9f3436561e59d98aad8c0a708ef0339952c2..55c62e287801d209010e96757263bfeaf7b5e1b3 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
@@ -283,7 +283,7 @@ ICodec_ScanlineDecoder* FPDFAPI_CreateFlateDecoder(
   int predictor = 0;
   int Colors = 0, BitsPerComponent = 0, Columns = 0;
   if (pParams) {
-    predictor = ((CPDF_Dictionary*)pParams)->GetInteger(FX_BSTRC("Predictor"));
+    predictor = pParams->GetInteger(FX_BSTRC("Predictor"));
     Colors = pParams->GetInteger(FX_BSTRC("Colors"), 1);
     BitsPerComponent = pParams->GetInteger(FX_BSTRC("BitsPerComponent"), 8);
     Columns = pParams->GetInteger(FX_BSTRC("Columns"), 1);
@@ -306,9 +306,8 @@ FX_DWORD FPDFAPI_FlateOrLZWDecode(FX_BOOL bLZW,
   FX_BOOL bEarlyChange = TRUE;
   int Colors = 0, BitsPerComponent = 0, Columns = 0;
   if (pParams) {
-    predictor = ((CPDF_Dictionary*)pParams)->GetInteger(FX_BSTRC("Predictor"));
-    bEarlyChange =
-        ((CPDF_Dictionary*)pParams)->GetInteger(FX_BSTRC("EarlyChange"), 1);
+    predictor = pParams->GetInteger(FX_BSTRC("Predictor"));
+    bEarlyChange = pParams->GetInteger(FX_BSTRC("EarlyChange"), 1);
     Colors = pParams->GetInteger(FX_BSTRC("Colors"), 1);
     BitsPerComponent = pParams->GetInteger(FX_BSTRC("BitsPerComponent"), 8);
     Columns = pParams->GetInteger(FX_BSTRC("Columns"), 1);
@@ -365,7 +364,9 @@ FX_BOOL PDF_DataDecode(const uint8_t* src_buf,
     int estimated_size =
         i == DecoderList.GetSize() - 1 ? last_estimated_size : 0;
     CFX_ByteString decoder = DecoderList[i];
-    CPDF_Dictionary* pParam = (CPDF_Dictionary*)ParamList[i];
+    // Use ToDictionary here because we can push NULL into the ParamList.
+    CPDF_Dictionary* pParam =
+        ToDictionary(static_cast<CPDF_Object*>(ParamList[i]));
     uint8_t* new_buf = NULL;
     FX_DWORD new_size = (FX_DWORD)-1;
     int offset = -1;