diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index 3cdc96a..d7fb18e 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -31,7 +31,6 @@
 #include "core/fpdfdoc/cpdf_action.h"
 #include "core/fxcodec/codec/ccodec_iccmodule.h"
 #include "core/fxcodec/fx_codec.h"
-#include "core/fxcrt/cfx_fixedbufgrow.h"
 #include "core/fxcrt/fx_memory.h"
 #include "core/fxcrt/maybe_owned.h"
 #include "third_party/base/stl_util.h"
@@ -574,8 +573,7 @@
                                          int image_width,
                                          int image_height,
                                          bool bTransMask) const {
-  CFX_FixedBufGrow<float, 16> srcbuf(m_nComponents);
-  float* src = srcbuf;
+  std::vector<float> src(m_nComponents);
   float R;
   float G;
   float B;
@@ -583,7 +581,7 @@
   for (int i = 0; i < pixels; i++) {
     for (uint32_t j = 0; j < m_nComponents; j++)
       src[j] = static_cast<float>(*src_buf++) / divisor;
-    GetRGB(src, &R, &G, &B);
+    GetRGB(src.data(), &R, &G, &B);
     *dest_buf++ = static_cast<int32_t>(B * 255);
     *dest_buf++ = static_cast<int32_t>(G * 255);
     *dest_buf++ = static_cast<int32_t>(R * 255);
@@ -1151,15 +1149,15 @@
       return false;
     }
   }
-  CFX_FixedBufGrow<float, 16> Comps(m_nBaseComponents);
-  float* comps = Comps;
+  std::vector<float> comps;
+  comps.reserve(m_nBaseComponents);
   const uint8_t* pTable = m_Table.raw_str();
   for (uint32_t i = 0; i < m_nBaseComponents; i++) {
-    comps[i] =
-        m_pCompMinMax[i * 2] +
-        m_pCompMinMax[i * 2 + 1] * pTable[index * m_nBaseComponents + i] / 255;
+    comps.push_back(m_pCompMinMax[i * 2] +
+                    m_pCompMinMax[i * 2 + 1] *
+                        pTable[index * m_nBaseComponents + i] / 255);
   }
-  return m_pBaseCS->GetRGB(comps, R, G, B);
+  return m_pBaseCS->GetRGB(comps.data(), R, G, B);
 }
 
 void CPDF_IndexedCS::EnableStdConversion(bool bEnabled) {
@@ -1216,32 +1214,21 @@
                                float* R,
                                float* G,
                                float* B) const {
-  if (m_Type == None)
+  if (m_Type == None || !m_pAltCS)
     return false;
 
   if (!m_pFunc) {
-    if (!m_pAltCS)
-      return false;
-
     int nComps = m_pAltCS->CountComponents();
-    CFX_FixedBufGrow<float, 16> results(nComps);
-    for (int i = 0; i < nComps; i++)
-      results[i] = *pBuf;
-    return m_pAltCS->GetRGB(results, R, G, B);
+    std::vector<float> results(nComps, *pBuf);
+    return m_pAltCS->GetRGB(results.data(), R, G, B);
   }
 
-  CFX_FixedBufGrow<float, 16> results(m_pFunc->CountOutputs());
+  std::vector<float> results2(m_pFunc->CountOutputs());
   int nresults = 0;
-  if (!m_pFunc->Call(pBuf, 1, results, &nresults) || nresults == 0)
+  if (!m_pFunc->Call(pBuf, 1, results2.data(), &nresults) || nresults == 0)
     return false;
 
-  if (m_pAltCS)
-    return m_pAltCS->GetRGB(results, R, G, B);
-
-  R = 0;
-  G = 0;
-  B = 0;
-  return false;
+  return m_pAltCS->GetRGB(results2.data(), R, G, B);
 }
 
 void CPDF_SeparationCS::EnableStdConversion(bool bEnabled) {
@@ -1296,14 +1283,14 @@
   if (!m_pFunc)
     return false;
 
-  CFX_FixedBufGrow<float, 16> results(m_pFunc->CountOutputs());
+  std::vector<float> results(m_pFunc->CountOutputs());
   int nresults = 0;
-  if (!m_pFunc->Call(pBuf, CountComponents(), results, &nresults) ||
+  if (!m_pFunc->Call(pBuf, CountComponents(), results.data(), &nresults) ||
       nresults == 0) {
     return false;
   }
 
-  return m_pAltCS->GetRGB(results, R, G, B);
+  return m_pAltCS->GetRGB(results.data(), R, G, B);
 }
 
 void CPDF_DeviceNCS::EnableStdConversion(bool bEnabled) {
diff --git a/core/fpdfapi/render/cpdf_dibsource.cpp b/core/fpdfapi/render/cpdf_dibsource.cpp
index 153491a..b8b91d2 100644
--- a/core/fpdfapi/render/cpdf_dibsource.cpp
+++ b/core/fpdfapi/render/cpdf_dibsource.cpp
@@ -764,8 +764,7 @@
   }
 
   int palette_count = 1 << (m_bpc * m_nComponents);
-  CFX_FixedBufGrow<float, 16> color_values(m_nComponents);
-  float* color_value = color_values;
+  std::vector<float> color_value(m_nComponents);
   for (int i = 0; i < palette_count; i++) {
     int color_data = i;
     for (uint32_t j = 0; j < m_nComponents; j++) {
@@ -782,11 +781,11 @@
       int nComponents = m_pColorSpace->CountComponents();
       std::vector<float> temp_buf(nComponents);
       for (int k = 0; k < nComponents; k++) {
-        temp_buf[k] = *color_value;
+        temp_buf[k] = color_value[0];
       }
       m_pColorSpace->GetRGB(temp_buf.data(), &R, &G, &B);
     } else {
-      m_pColorSpace->GetRGB(color_value, &R, &G, &B);
+      m_pColorSpace->GetRGB(color_value.data(), &R, &G, &B);
     }
     SetPaletteArgb(i, ArgbEncode(255, FXSYS_round(R * 255),
                                  FXSYS_round(G * 255), FXSYS_round(B * 255)));
@@ -834,8 +833,7 @@
   if (TranslateScanline24bppDefaultDecode(dest_scan, src_scan))
     return;
 
-  CFX_FixedBufGrow<float, 16> color_values1(m_nComponents);
-  float* color_values = color_values1;
+  std::vector<float> color_values(m_nComponents);
   float R = 0.0f;
   float G = 0.0f;
   float B = 0.0f;
@@ -863,7 +861,7 @@
       G = (1.0f - color_values[1]) * k;
       B = (1.0f - color_values[2]) * k;
     } else if (m_Family != PDFCS_PATTERN) {
-      m_pColorSpace->GetRGB(color_values, &R, &G, &B);
+      m_pColorSpace->GetRGB(color_values.data(), &R, &G, &B);
     }
     R = pdfium::clamp(R, 0.0f, 1.0f);
     G = pdfium::clamp(G, 0.0f, 1.0f);
diff --git a/core/fpdfapi/render/cpdf_renderstatus.cpp b/core/fpdfapi/render/cpdf_renderstatus.cpp
index f926157..708d707 100644
--- a/core/fpdfapi/render/cpdf_renderstatus.cpp
+++ b/core/fpdfapi/render/cpdf_renderstatus.cpp
@@ -48,7 +48,6 @@
 #include "core/fpdfapi/render/cpdf_type3cache.h"
 #include "core/fpdfdoc/cpdf_occontext.h"
 #include "core/fxcrt/autorestorer.h"
-#include "core/fxcrt/cfx_fixedbufgrow.h"
 #include "core/fxcrt/fx_fallthrough.h"
 #include "core/fxcrt/fx_safe_types.h"
 #include "core/fxcrt/maybe_owned.h"
@@ -151,9 +150,7 @@
   float y_span = end_y - start_y;
   float axis_len_square = (x_span * x_span) + (y_span * y_span);
 
-  CFX_FixedBufGrow<float, 16> result_array(total_results);
-  float* pResults = result_array;
-  memset(pResults, 0, total_results * sizeof(float));
+  std::vector<float> results(total_results);
   uint32_t rgb_array[kShadingSteps];
   for (int i = 0; i < kShadingSteps; i++) {
     float input = (t_max - t_min) * i / kShadingSteps + t_min;
@@ -161,14 +158,14 @@
     for (const auto& func : funcs) {
       if (func) {
         int nresults = 0;
-        if (func->Call(&input, 1, pResults + offset, &nresults))
+        if (func->Call(&input, 1, results.data() + offset, &nresults))
           offset += nresults;
       }
     }
     float R = 0.0f;
     float G = 0.0f;
     float B = 0.0f;
-    pCS->GetRGB(pResults, &R, &G, &B);
+    pCS->GetRGB(results.data(), &R, &G, &B);
     rgb_array[i] =
         FXARGB_TODIB(FXARGB_MAKE(alpha, FXSYS_round(R * 255),
                                  FXSYS_round(G * 255), FXSYS_round(B * 255)));
@@ -237,9 +234,7 @@
     bEndExtend = !!pArray->GetIntegerAt(1);
   }
 
-  CFX_FixedBufGrow<float, 16> result_array(total_results);
-  float* pResults = result_array;
-  memset(pResults, 0, total_results * sizeof(float));
+  std::vector<float> results(total_results);
   uint32_t rgb_array[kShadingSteps];
   for (int i = 0; i < kShadingSteps; i++) {
     float input = (t_max - t_min) * i / kShadingSteps + t_min;
@@ -247,14 +242,14 @@
     for (const auto& func : funcs) {
       if (func) {
         int nresults;
-        if (func->Call(&input, 1, pResults + offset, &nresults))
+        if (func->Call(&input, 1, results.data() + offset, &nresults))
           offset += nresults;
       }
     }
     float R = 0.0f;
     float G = 0.0f;
     float B = 0.0f;
-    pCS->GetRGB(pResults, &R, &G, &B);
+    pCS->GetRGB(results.data(), &R, &G, &B);
     rgb_array[i] =
         FXARGB_TODIB(FXARGB_MAKE(alpha, FXSYS_round(R * 255),
                                  FXSYS_round(G * 255), FXSYS_round(B * 255)));
@@ -366,9 +361,7 @@
   int height = pBitmap->GetHeight();
   int pitch = pBitmap->GetPitch();
 
-  CFX_FixedBufGrow<float, 16> result_array(total_results);
-  float* pResults = result_array;
-  memset(pResults, 0, total_results * sizeof(float));
+  std::vector<float> results(total_results);
   for (int row = 0; row < height; row++) {
     uint32_t* dib_buf = (uint32_t*)(pBitmap->GetBuffer() + row * pitch);
     for (int column = 0; column < width; column++) {
@@ -382,7 +375,7 @@
       for (const auto& func : funcs) {
         if (func) {
           int nresults;
-          if (func->Call(input, 2, pResults + offset, &nresults))
+          if (func->Call(input, 2, results.data() + offset, &nresults))
             offset += nresults;
         }
       }
@@ -390,7 +383,7 @@
       float R = 0.0f;
       float G = 0.0f;
       float B = 0.0f;
-      pCS->GetRGB(pResults, &R, &G, &B);
+      pCS->GetRGB(results.data(), &R, &G, &B);
       dib_buf[column] = FXARGB_TODIB(FXARGB_MAKE(
           alpha, (int32_t)(R * 255), (int32_t)(G * 255), (int32_t)(B * 255)));
     }
@@ -2054,13 +2047,14 @@
     CPDF_Array* pBackColor = pDict->GetArrayFor("Background");
     if (pBackColor &&
         pBackColor->GetCount() >= pColorSpace->CountComponents()) {
-      CFX_FixedBufGrow<float, 16> comps(pColorSpace->CountComponents());
+      std::vector<float> comps;
+      comps.reserve(pColorSpace->CountComponents());
       for (uint32_t i = 0; i < pColorSpace->CountComponents(); i++)
-        comps[i] = pBackColor->GetNumberAt(i);
+        comps.push_back(pBackColor->GetNumberAt(i));
       float R = 0.0f;
       float G = 0.0f;
       float B = 0.0f;
-      pColorSpace->GetRGB(comps, &R, &G, &B);
+      pColorSpace->GetRGB(comps.data(), &R, &G, &B);
       background = ArgbEncode(255, (int32_t)(R * 255), (int32_t)(G * 255),
                               (int32_t)(B * 255));
     }
@@ -2584,23 +2578,13 @@
         color_space_family = pCS->GetFamily();
 
         float R, G, B;
-        uint32_t comps = 8;
-        if (pCS->CountComponents() > comps) {
-          comps = pCS->CountComponents();
-        }
-        CFX_FixedBufGrow<float, 8> float_array(comps);
-        float* pFloats = float_array;
-        FX_SAFE_UINT32 num_floats = comps;
-        num_floats *= sizeof(float);
-        if (!num_floats.IsValid()) {
-          return nullptr;
-        }
-        memset(pFloats, 0, num_floats.ValueOrDie());
-        size_t count = pBC->GetCount() > 8 ? 8 : pBC->GetCount();
+        uint32_t comps = std::max(8u, pCS->CountComponents());
+        std::vector<float> floats(comps);
+        size_t count = std::min<size_t>(8, pBC->GetCount());
         for (size_t i = 0; i < count; i++) {
-          pFloats[i] = pBC->GetNumberAt(i);
+          floats[i] = pBC->GetNumberAt(i);
         }
-        pCS->GetRGB(pFloats, &R, &G, &B);
+        pCS->GetRGB(floats.data(), &R, &G, &B);
         back_color = 0xff000000 | ((int32_t)(R * 255) << 16) |
                      ((int32_t)(G * 255) << 8) | (int32_t)(B * 255);
         m_pContext->GetDocument()->GetPageData()->ReleaseColorSpace(pCSObj);
@@ -2633,11 +2617,11 @@
   int src_pitch = bitmap.GetPitch();
   std::vector<uint8_t> transfers(256);
   if (pFunc) {
-    CFX_FixedBufGrow<float, 16> results(pFunc->CountOutputs());
+    std::vector<float> results(pFunc->CountOutputs());
     for (int i = 0; i < 256; i++) {
       float input = (float)i / 255.0f;
       int nresult;
-      pFunc->Call(&input, 1, results, &nresult);
+      pFunc->Call(&input, 1, results.data(), &nresult);
       transfers[i] = FXSYS_round(results[0] * 255);
     }
   } else {
diff --git a/core/fxcodec/codec/fx_codec_icc.cpp b/core/fxcodec/codec/fx_codec_icc.cpp
index 29b37d1..458816e 100644
--- a/core/fxcodec/codec/fx_codec_icc.cpp
+++ b/core/fxcodec/codec/fx_codec_icc.cpp
@@ -5,10 +5,10 @@
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <memory>
+#include <vector>
 
 #include "core/fxcodec/codec/ccodec_iccmodule.h"
 #include "core/fxcodec/codec/codec_int.h"
-#include "core/fxcrt/cfx_fixedbufgrow.h"
 
 namespace {
 
@@ -124,19 +124,16 @@
   uint32_t nSrcComponents = m_nComponents;
   uint8_t output[4];
   if (pTransform->m_bLab) {
-    CFX_FixedBufGrow<double, 16> inputs(nSrcComponents);
-    double* input = inputs;
-    for (uint32_t i = 0; i < nSrcComponents; ++i)
-      input[i] = pSrcValues[i];
-    cmsDoTransform(pTransform->m_hTransform, input, output, 1);
+    std::vector<double> input(pSrcValues, pSrcValues + nSrcComponents);
+    cmsDoTransform(pTransform->m_hTransform, input.data(), output, 1);
   } else {
-    CFX_FixedBufGrow<uint8_t, 16> inputs(nSrcComponents);
-    uint8_t* input = inputs;
+    std::vector<uint8_t> input;
+    input.reserve(nSrcComponents);
     for (uint32_t i = 0; i < nSrcComponents; ++i) {
-      input[i] =
-          pdfium::clamp(static_cast<int>(pSrcValues[i] * 255.0f), 0, 255);
+      input.push_back(
+          pdfium::clamp(static_cast<int>(pSrcValues[i] * 255.0f), 0, 255));
     }
-    cmsDoTransform(pTransform->m_hTransform, input, output, 1);
+    cmsDoTransform(pTransform->m_hTransform, input.data(), output, 1);
   }
   pDestValues[0] = output[2] / 255.0f;
   pDestValues[1] = output[1] / 255.0f;
diff --git a/core/fxge/apple/fx_apple_platform.cpp b/core/fxge/apple/fx_apple_platform.cpp
index 1801814..013be8f 100644
--- a/core/fxge/apple/fx_apple_platform.cpp
+++ b/core/fxge/apple/fx_apple_platform.cpp
@@ -5,8 +5,8 @@
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <memory>
+#include <vector>
 
-#include "core/fxcrt/cfx_fixedbufgrow.h"
 #include "core/fxcrt/fx_system.h"
 
 #ifndef _SKIA_SUPPORT_
@@ -57,11 +57,12 @@
     if (!pFont->GetPlatformFont())
       return false;
   }
-  CFX_FixedBufGrow<uint16_t, 32> glyph_indices(nChars);
-  CFX_FixedBufGrow<CGPoint, 32> glyph_positions(nChars);
+  std::vector<uint16_t> glyph_indices;
+  glyph_indices.reserve(nChars);
+  std::vector<CGPoint> glyph_positions(nChars);
   for (int i = 0; i < nChars; i++) {
-    glyph_indices[i] =
-        pCharPos[i].m_ExtGID ? pCharPos[i].m_ExtGID : pCharPos[i].m_GlyphIndex;
+    glyph_indices.push_back(pCharPos[i].m_ExtGID ? pCharPos[i].m_ExtGID
+                                                 : pCharPos[i].m_GlyphIndex);
     if (bNegSize)
       glyph_positions[i].x = -pCharPos[i].m_Origin.x;
     else
@@ -76,9 +77,9 @@
     new_matrix.d = -new_matrix.d;
   }
   quartz2d.setGraphicsTextMatrix(pContext, &new_matrix);
-  return quartz2d.drawGraphicsString(pContext, pFont->GetPlatformFont(),
-                                     font_size, glyph_indices, glyph_positions,
-                                     nChars, argb, nullptr);
+  return quartz2d.drawGraphicsString(
+      pContext, pFont->GetPlatformFont(), font_size, glyph_indices.data(),
+      glyph_positions.data(), nChars, argb, nullptr);
 }
 
 }  // namespace