Fix two memory leaks from pdfium_unittests

- remove redundant alloc in fx_codec_jpx_unittest.cpp
- free memory allocated by HexDecode calls in fpdf_parser_decode_unittest.cpp

BUG=PDFium:239
R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1467183006 .
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_unittest.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_unittest.cpp
index 95d7c84..3318bcd 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_unittest.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_unittest.cpp
@@ -14,6 +14,7 @@
     EXPECT_EQ(0, HexDecode(src, 0, dest, dest_size));
     EXPECT_EQ(0, dest_size);
     EXPECT_EQ('\0', dest[0]);
+    FX_Free(dest);
   }
 
   {
@@ -25,6 +26,7 @@
     EXPECT_EQ(2, dest_size);
     EXPECT_EQ(18, dest[0]);
     EXPECT_EQ(172, dest[1]);
+    FX_Free(dest);
   }
 
   {
@@ -36,6 +38,7 @@
     EXPECT_EQ(2, dest_size);
     EXPECT_EQ(18, dest[0]);
     EXPECT_EQ(160, dest[1]);
+    FX_Free(dest);
   }
 
   {
@@ -47,5 +50,6 @@
     EXPECT_EQ(2, dest_size);
     EXPECT_EQ(18, dest[0]);
     EXPECT_EQ(172, dest[1]);
+    FX_Free(dest);
   }
 }
diff --git a/core/src/fxcodec/codec/fx_codec_jpx_unittest.cpp b/core/src/fxcodec/codec/fx_codec_jpx_unittest.cpp
index fe552d2..4139fbd 100644
--- a/core/src/fxcodec/codec/fx_codec_jpx_unittest.cpp
+++ b/core/src/fxcodec/codec/fx_codec_jpx_unittest.cpp
@@ -474,8 +474,6 @@
   u.h = 16;
   u.prec = 8;
   u.bpp = 8;
-  u.data = FX_Alloc(OPJ_INT32, u.w * u.h);
-  memset(u.data, 0, u.w * u.h * sizeof(OPJ_INT32));
   opj_image_comp_t v;
   memset(&v, 0, sizeof(v));
   v.dx = 1;
@@ -484,8 +482,6 @@
   v.h = 16;
   v.prec = 8;
   v.bpp = 8;
-  v.data = FX_Alloc(OPJ_INT32, v.w * v.h);
-  memset(v.data, 0, v.w * v.h * sizeof(OPJ_INT32));
   opj_image_comp_t y;
   memset(&y, 0, sizeof(y));
   y.dx = 1;