Fix four annoying warnings:
Two "set but unused", one of which is surely an artifact from
copying code around, and the other which ought to be used for
the sake of clarity.

Two are unknown "optimize" pragmas, remove them since the code
has been shipped for years on other platforms under full optimization.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1148353002
diff --git a/core/src/fpdfapi/fpdf_edit/fpdf_edit_image.cpp b/core/src/fpdfapi/fpdf_edit/fpdf_edit_image.cpp
index a5a91eb..9096bf9 100644
--- a/core/src/fpdfapi/fpdf_edit/fpdf_edit_image.cpp
+++ b/core/src/fpdfapi/fpdf_edit/fpdf_edit_image.cpp
@@ -190,8 +190,10 @@
         }
     }
     const CFX_DIBitmap* pMaskBitmap = NULL;
+    FX_BOOL bDeleteMask = FALSE;
     if (pBitmap->HasAlpha()) {
         pMaskBitmap = pBitmap->GetAlphaMask();
+        bDeleteMask = TRUE;
     }
     if (!pMaskBitmap && pMask) {
         FXDIB_Format maskFormat = pMask->GetFormat();
@@ -204,7 +206,6 @@
         FX_INT32 maskHeight = pMaskBitmap->GetHeight();
         FX_LPBYTE mask_buf = NULL;
         FX_STRSIZE mask_size;
-        FX_BOOL bDeleteMask = TRUE;
         CPDF_Dictionary* pMaskDict = new CPDF_Dictionary;
         pMaskDict->SetAtName(FX_BSTRC("Type"), FX_BSTRC("XObject"));
         pMaskDict->SetAtName(FX_BSTRC("Subtype"), FX_BSTRC("Image"));
@@ -223,24 +224,20 @@
                 FXSYS_memcpy32(mask_buf + a * maskWidth, pMaskBitmap->GetScanline(a), maskWidth);
             }
         }
-        if (pMaskDict) {
-            pMaskDict->SetAtInteger(FX_BSTRC("Length"), mask_size);
-            CPDF_Stream* pMaskStream = NULL;
-            if (bUseMatte) {
-                int a, r, g, b;
-                ArgbDecode(*(pParam->pMatteColor), a, r, g, b);
-                CPDF_Array* pMatte = new CPDF_Array;
-                pMatte->AddInteger(r);
-                pMatte->AddInteger(g);
-                pMatte->AddInteger(b);
-                pMaskDict->SetAt(FX_BSTRC("Matte"), pMatte);
-            }
-            pMaskStream = new CPDF_Stream(mask_buf, mask_size, pMaskDict);
-            m_pDocument->AddIndirectObject(pMaskStream);
-            bDeleteMask = FALSE;
-            pDict->SetAtReference(FX_BSTRC("SMask"), m_pDocument, pMaskStream);
+        pMaskDict->SetAtInteger(FX_BSTRC("Length"), mask_size);
+        if (bUseMatte) {
+            int a, r, g, b;
+            ArgbDecode(*(pParam->pMatteColor), a, r, g, b);
+            CPDF_Array* pMatte = new CPDF_Array;
+            pMatte->AddInteger(r);
+            pMatte->AddInteger(g);
+            pMatte->AddInteger(b);
+            pMaskDict->SetAt(FX_BSTRC("Matte"), pMatte);
         }
-        if (pBitmap->HasAlpha()) {
+        CPDF_Stream* pMaskStream = new CPDF_Stream(mask_buf, mask_size, pMaskDict);
+        m_pDocument->AddIndirectObject(pMaskStream);
+        pDict->SetAtReference(FX_BSTRC("SMask"), m_pDocument, pMaskStream);
+        if (bDeleteMask) {
             delete pMaskBitmap;
         }
     }
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_func.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_func.cpp
index 8ec490a..924c88e 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_func.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_func.cpp
@@ -73,7 +73,6 @@
         }
     }
 }
-#pragma optimize( "", off )
 FX_BOOL CPDF_PSProc::Execute(CPDF_PSEngine* pEngine)
 {
     int size = m_Operators.GetSize();
@@ -107,7 +106,6 @@
     }
     return TRUE;
 }
-#pragma optimize( "", on )
 CPDF_PSEngine::CPDF_PSEngine()
 {
     m_StackCount = 0;
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
index 691981c..d18caab 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
@@ -232,11 +232,9 @@
         int nComps, int bpc, const CPDF_Dictionary* pParams)
 {
     int predictor = 0;
-    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);
         Colors = pParams->GetInteger(FX_BSTRC("Colors"), 1);
         BitsPerComponent = pParams->GetInteger(FX_BSTRC("BitsPerComponent"), 8);
         Columns = pParams->GetInteger(FX_BSTRC("Columns"), 1);