Delete useless CFX_GlyphCache::RenderGlyph_Nativetext()

This method just returns nullptr. Delete it and delete the calling code
that handles when RenderGlyph_Nativetext() returns a non-null value.
Rename some variables in the calling code along the way.

Change-Id: I6ba91d23263d05eacdb36f9b406955ec181a4116
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/139450
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fxge/apple/fx_apple_impl.cpp

diff --git a/core/fxge/apple/fx_apple_impl.cpp b/core/fxge/apple/fx_apple_impl.cpp
index 0cb5226..65868eb 100644
--- a/core/fxge/apple/fx_apple_impl.cpp
+++ b/core/fxge/apple/fx_apple_impl.cpp
@@ -177,15 +177,6 @@
 
 }  // namespace pdfium
 
-std::unique_ptr<CFX_GlyphBitmap> CFX_GlyphCache::RenderGlyph_Nativetext(
-    const CFX_Font* font,
-    uint32_t glyph_index,
-    const CFX_Matrix& matrix,
-    int dest_width,
-    FontAntiAliasingMode anti_alias) {
-  return nullptr;
-}
-
 void CFX_Font::ReleasePlatformResource() {
   if (platform_font_) {
     CQuartz2D& quartz2d =

core/fxge/cfx_glyphcache.cpp

diff --git a/core/fxge/cfx_glyphcache.cpp b/core/fxge/cfx_glyphcache.cpp
index 0dafc22..01fddab 100644
--- a/core/fxge/cfx_glyphcache.cpp
+++ b/core/fxge/cfx_glyphcache.cpp
@@ -186,33 +186,12 @@
 #if BUILDFLAG(IS_APPLE)
   DCHECK(!CFX_DefaultRenderDevice::UseSkiaRenderer());
 
-  std::unique_ptr<CFX_GlyphBitmap> pGlyphBitmap;
   auto it = size_map_.find(FaceGlyphsKey);
   if (it != size_map_.end()) {
-    SizeGlyphCache* pSizeCache = &(it->second);
-    auto it2 = pSizeCache->find(glyph_index);
-    if (it2 != pSizeCache->end()) {
-      return it2->second.get();
-    }
-
-    pGlyphBitmap = RenderGlyph_Nativetext(font, glyph_index, matrix, dest_width,
-                                          anti_alias);
-    if (pGlyphBitmap) {
-      CFX_GlyphBitmap* pResult = pGlyphBitmap.get();
-      (*pSizeCache)[glyph_index] = std::move(pGlyphBitmap);
-      return pResult;
-    }
-  } else {
-    pGlyphBitmap = RenderGlyph_Nativetext(font, glyph_index, matrix, dest_width,
-                                          anti_alias);
-    if (pGlyphBitmap) {
-      CFX_GlyphBitmap* pResult = pGlyphBitmap.get();
-
-      SizeGlyphCache cache;
-      cache[glyph_index] = std::move(pGlyphBitmap);
-
-      size_map_[FaceGlyphsKey] = std::move(cache);
-      return pResult;
+    SizeGlyphCache& size_glyph_cache = it->second;
+    auto size_glyph_it = size_glyph_cache.find(glyph_index);
+    if (size_glyph_it != size_glyph_cache.end()) {
+      return size_glyph_it->second.get();
     }
   }
   UniqueKeyGen keygen2(font, matrix, dest_width, anti_alias,

core/fxge/cfx_glyphcache.h

diff --git a/core/fxge/cfx_glyphcache.h b/core/fxge/cfx_glyphcache.h
index d319379..118e4b0 100644
--- a/core/fxge/cfx_glyphcache.h
+++ b/core/fxge/cfx_glyphcache.h
@@ -70,12 +70,6 @@
                                                const CFX_Matrix& matrix,
                                                int dest_width,
                                                FontAntiAliasingMode anti_alias);
-  std::unique_ptr<CFX_GlyphBitmap> RenderGlyph_Nativetext(
-      const CFX_Font* font,
-      uint32_t glyph_index,
-      const CFX_Matrix& matrix,
-      int dest_width,
-      FontAntiAliasingMode anti_alias);
   CFX_GlyphBitmap* LookUpGlyphBitmap(const CFX_Font* font,
                                      const CFX_Matrix& matrix,
                                      const ByteString& FaceGlyphsKey,