Make CPDF_Object::GetString() a virtual method.

core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp

Index: core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
index ce29baf738f8b5e3702132cd3882303a6334bb24..6ff0bfb468a407910a1d52804aa1415dfa9fc538 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
@@ -486,7 +486,8 @@ FX_BOOL CPDF_DIBSource::LoadColorInfo(CPDF_Dictionary* pFormResources, CPDF_Dict
                     }
                 } else if (pFilter->GetType() == PDFOBJ_ARRAY) {
                     CPDF_Array* pArray = (CPDF_Array*)pFilter;
-                    if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("JPXDecode")) {
+                    int count = pArray->GetCount() - 1;
+                    if (pArray->GetStringAt(count) == "JPXDecode") {
                         m_bDoBpcCheck = FALSE;
                         return TRUE;
                     }
@@ -944,12 +945,13 @@ void CPDF_DIBSource::ValidateDictParam()
             }
         } else if (pFilter->GetType() == PDFOBJ_ARRAY) {
             CPDF_Array *pArray = (CPDF_Array *)pFilter;
-            if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("CCITTFaxDecode") ||
-                    pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("JBIG2Decode")) {
+            int count = pArray->GetCount() - 1;
+            if (pArray->GetStringAt(count) == "CCITTFaxDecode" ||
+                pArray->GetStringAt(count) == "JBIG2Decode") {
                 m_bpc = 1;
                 m_nComponents = 1;
             }
-            if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("DCTDecode")) {
+            if (pArray->GetStringAt(count) == "DCTDecode") {

[Tom Sepez, 2015/07/16 20:24:46]

nit: is this |else if|?

                 // Previously, pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("RunLengthDecode") was checked in the "if" statement as well,
                 // but too many documents don't conform to it.
                 m_bpc = 8;