diff --git a/core/fpdfapi/render/fpdf_progressive_render_embeddertest.cpp b/core/fpdfapi/render/fpdf_progressive_render_embeddertest.cpp
index a1d6ee6..650c63a 100644
--- a/core/fpdfapi/render/fpdf_progressive_render_embeddertest.cpp
+++ b/core/fpdfapi/render/fpdf_progressive_render_embeddertest.cpp
@@ -21,13 +21,13 @@
 constexpr FX_ARGB kWhite = 0xFFFFFFFF;
 
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 static constexpr char kAnnotationStampWithApBaseContentChecksum[] =
     "fbd62f1df1cae1fd2fbf5a24bed6b4cd";
 #else
 static constexpr char kAnnotationStampWithApBaseContentChecksum[] =
     "44e6dd3c36d8bbfb38d306b442e61241";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 #else
 #if defined(OS_WIN)
 static constexpr char kAnnotationStampWithApBaseContentChecksum[] =
diff --git a/core/fxcrt/cfx_datetime.cpp b/core/fxcrt/cfx_datetime.cpp
index 896aa7b..3db9a98 100644
--- a/core/fxcrt/cfx_datetime.cpp
+++ b/core/fxcrt/cfx_datetime.cpp
@@ -9,8 +9,8 @@
 #include "build/build_config.h"
 #include "core/fxcrt/fx_system.h"
 
-#if defined(OS_ANDROID) || defined(OS_LINUX) || defined(OS_APPLE) || \
-    defined(OS_ASMJS)
+#if defined(OS_ANDROID) || defined(OS_LINUX) || defined(OS_CHROMEOS) || \
+    defined(OS_APPLE) || defined(OS_ASMJS)
 #include <sys/time.h>
 #include <time.h>
 #endif
diff --git a/core/fxge/cfx_font.cpp b/core/fxge/cfx_font.cpp
index c8b860c..35e136d 100644
--- a/core/fxge/cfx_font.cpp
+++ b/core/fxge/cfx_font.cpp
@@ -221,7 +221,8 @@
     {FX_CHARSET_ShiftJIS, "MS Gothic"},
     {FX_CHARSET_Hangul, "Batang"},
     {FX_CHARSET_MSWin_Cyrillic, "Arial"},
-#if defined(OS_LINUX) || defined(OS_ASMJS) || defined(OS_APPLE)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_ASMJS) || \
+    defined(OS_APPLE)
     {FX_CHARSET_MSWin_EasternEuropean, "Arial"},
 #else
     {FX_CHARSET_MSWin_EasternEuropean, "Tahoma"},
diff --git a/core/fxge/cfx_fontmapper.cpp b/core/fxge/cfx_fontmapper.cpp
index 485adc2..feca121 100644
--- a/core/fxge/cfx_fontmapper.cpp
+++ b/core/fxge/cfx_fontmapper.cpp
@@ -154,13 +154,13 @@
     {"ForteMT", "Forte"},
 };
 
-#if defined(OS_LINUX) || defined(OS_ASMJS)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_ASMJS)
 const char kNarrowFamily[] = "LiberationSansNarrow";
 #elif defined(OS_ANDROID)
 const char kNarrowFamily[] = "RobotoCondensed";
 #else
 const char kNarrowFamily[] = "ArialNarrow";
-#endif  // defined(OS_LINUX) || defined(OS_ASMJS)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_ASMJS)
 
 ByteString TT_NormalizeName(const char* family) {
   ByteString norm(family);
diff --git a/core/fxge/fx_ge_linux.cpp b/core/fxge/fx_ge_linux.cpp
index 8fcc921..72cb263 100644
--- a/core/fxge/fx_ge_linux.cpp
+++ b/core/fxge/fx_ge_linux.cpp
@@ -16,7 +16,7 @@
 #include "core/fxge/systemfontinfo_iface.h"
 #include "third_party/base/stl_util.h"
 
-#if !defined(OS_LINUX) && !defined(OS_ASMJS)
+#if !defined(OS_LINUX) && !defined(OS_CHROMEOS) && !defined(OS_ASMJS)
 #error "Included on the wrong platform"
 #endif
 
diff --git a/fpdfsdk/fpdf_annot_embeddertest.cpp b/fpdfsdk/fpdf_annot_embeddertest.cpp
index df5f363..455ab0b 100644
--- a/fpdfsdk/fpdf_annot_embeddertest.cpp
+++ b/fpdfsdk/fpdf_annot_embeddertest.cpp
@@ -1016,7 +1016,7 @@
 
 TEST_F(FPDFAnnotEmbedderTest, AddAndModifyPath) {
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
   static const char kMd5ModifiedPath[] = "d76382fd57fafad0233f7549f871dafa";
   static const char kMd5TwoPaths[] = "323151317b8cb62130546c7b8d70f622";
   static const char kMd5NewAnnot[] = "9a3b02d876620d19787549ee1100b63c";
@@ -1024,7 +1024,7 @@
   static const char kMd5ModifiedPath[] = "c9ba60887a312370d9a32198aa53aca4";
   static const char kMd5TwoPaths[] = "0768d56373094fcdf4ddf3f3364c006f";
   static const char kMd5NewAnnot[] = "6f7e1c189bcfac90ffccf2a527857006";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 #else
 #if defined(OS_WIN)
   static const char kMd5ModifiedPath[] = "a7a8d675a6ddbcbdfecee65a33ba19e1";
@@ -1233,13 +1233,13 @@
 #endif
 TEST_F(FPDFAnnotEmbedderTest, MAYBE_AddAndModifyImage) {
 #if defined(_SKIA_SUPPORT_PATHS_)
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
   static const char kMd5NewImage[] = "26a8eb30937226a677839379e0d7ae1a";
   static const char kMd5ModifiedImage[] = "2985114b32ba1a96be78ee643fe31aa5";
 #else
   static const char kMd5NewImage[] = "14012ab500b4671fa73dd760129a8a93";
   static const char kMd5ModifiedImage[] = "5f97f98f58ed04dc393f31460485f1a2";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 #else
 #if defined(OS_APPLE)
   static const char kMd5NewImage[] = "dd18709d90c245a12ce0b8c4d092bea9";
@@ -1325,13 +1325,13 @@
 
 TEST_F(FPDFAnnotEmbedderTest, AddAndModifyText) {
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
   static const char kMd5NewText[] = "c9d853a5fb6bca31e9696ccc4462c74a";
   static const char kMd5ModifiedText[] = "bc681fa9174223983c5e4357e919d36c";
 #else
   static const char kMd5NewText[] = "4aaa34e9df2e41d621dbd81b1d535c48";
   static const char kMd5ModifiedText[] = "d6ea20beb7834ef4b6d370581ce425fc";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 #else
 #if defined(OS_WIN)
   static const char kMd5NewText[] = "204cc01749a70b8afc246a4ca33c7eb6";
@@ -1472,11 +1472,11 @@
   UnloadPage(page);
 
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
   static const char kMd5[] = "7a2b712ca88d7b71f125ea3f9c88e57a";
 #else
   static const char kMd5[] = "626d25c5aa5baf67d22d9a0e1c23f6aa";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 #else
 #if defined(OS_APPLE)
   static const char kMd5[] = "5e7e185b386ad21ca83b0287268c50fb";
diff --git a/fpdfsdk/fpdf_edit_embeddertest.cpp b/fpdfsdk/fpdf_edit_embeddertest.cpp
index dcbc16d..ffd1d51 100644
--- a/fpdfsdk/fpdf_edit_embeddertest.cpp
+++ b/fpdfsdk/fpdf_edit_embeddertest.cpp
@@ -2717,7 +2717,7 @@
 }
 
 // TODO(npm): Add tests using Japanese fonts in other OS.
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 // TODO(crbug.com/pdfium/11): Fix this test and enable.
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
 #define MAYBE_AddCIDFontText DISABLED_AddCIDFontText
@@ -2776,7 +2776,7 @@
 
   VerifySavedDocument(612, 792, md5);
 }
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 
 // TODO(crbug.com/pdfium/11): Fix this test and enable.
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
diff --git a/fpdfsdk/fpdf_transformpage_embeddertest.cpp b/fpdfsdk/fpdf_transformpage_embeddertest.cpp
index d938943..3f57d74 100644
--- a/fpdfsdk/fpdf_transformpage_embeddertest.cpp
+++ b/fpdfsdk/fpdf_transformpage_embeddertest.cpp
@@ -8,7 +8,7 @@
 #include "testing/embedder_test.h"
 #include "testing/embedder_test_constants.h"
 
-#if defined(OS_LINUX) || defined(OS_FUCHSIA)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_FUCHSIA)
 #include "third_party/base/test/scoped_locale.h"
 #endif
 
@@ -473,7 +473,7 @@
   }
 }
 
-#if defined(OS_LINUX) || defined(OS_FUCHSIA)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_FUCHSIA)
 TEST_F(FPDFTransformEmbedderTest, TransFormWithClipAndSaveWithLocale) {
   pdfium::base::ScopedLocale scoped_locale("da_DK.UTF-8");
 
@@ -529,4 +529,4 @@
     CloseSavedDocument();
   }
 }
-#endif  // defined(OS_LINUX) || defined(OS_FUCHSIA)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_FUCHSIA)
diff --git a/testing/embedder_test_constants.cpp b/testing/embedder_test_constants.cpp
index 1ea6abe..748c372 100644
--- a/testing/embedder_test_constants.cpp
+++ b/testing/embedder_test_constants.cpp
@@ -9,13 +9,13 @@
 namespace pdfium {
 
 #if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 const char kAnnotationStampWithApChecksum[] =
     "db83eaadc92967e3ac9bebfc6178ca75";
 #else
 const char kAnnotationStampWithApChecksum[] =
     "3c87b4a8e51245964357fb5f5fbc612b";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 #else
 #if defined(OS_WIN)
 const char kAnnotationStampWithApChecksum[] =
diff --git a/third_party/base/allocator/partition_allocator/page_allocator_internals_posix.h b/third_party/base/allocator/partition_allocator/page_allocator_internals_posix.h
index 68e808c..8136ad2 100644
--- a/third_party/base/allocator/partition_allocator/page_allocator_internals_posix.h
+++ b/third_party/base/allocator/partition_allocator/page_allocator_internals_posix.h
@@ -16,7 +16,7 @@
 #if defined(OS_ANDROID)
 #include <sys/prctl.h>
 #endif
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 #include <sys/resource.h>
 
 #include <algorithm>
diff --git a/xfa/fgas/font/cfx_fontsourceenum_file.cpp b/xfa/fgas/font/cfx_fontsourceenum_file.cpp
index 2eaf150..f4c4d08 100644
--- a/xfa/fgas/font/cfx_fontsourceenum_file.cpp
+++ b/xfa/fgas/font/cfx_fontsourceenum_file.cpp
@@ -15,7 +15,7 @@
 constexpr char kFolderSeparator = '/';
 
 constexpr const char* kFontFolders[] = {
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
     "/usr/share/fonts",
     "/usr/share/X11/fonts/Type1",
     "/usr/share/X11/fonts/TTF",
diff --git a/xfa/fwl/cfwl_edit_embeddertest.cpp b/xfa/fwl/cfwl_edit_embeddertest.cpp
index d44b8d0..27679a3 100644
--- a/xfa/fwl/cfwl_edit_embeddertest.cpp
+++ b/xfa/fwl/cfwl_edit_embeddertest.cpp
@@ -162,11 +162,11 @@
   // abcde
   // fghij|
   {
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
     const char kFilledMultilineMD5[] = "fc1f4d5fdb2c5755005fc525b0a60ec9";
 #else
     const char kFilledMultilineMD5[] = "a5654e027d8b1667c20f3b86d1918003";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
     ScopedFPDFBitmap page_bitmap =
         RenderLoadedPageWithFlags(page(), FPDF_ANNOT);
     CompareBitmap(page_bitmap.get(), 612, 792, kFilledMultilineMD5);
@@ -187,11 +187,11 @@
   // Should look like:
   // abcde|ghij
   {
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
     const char kMultilineBackspaceMD5[] = "8bb62a8100ff1e1cc113d4033e0d824e";
 #else
     const char kMultilineBackspaceMD5[] = "a2f1dcab92bb1fb7c2f9ccc70100c989";
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
     ScopedFPDFBitmap page_bitmap =
         RenderLoadedPageWithFlags(page(), FPDF_ANNOT);
     CompareBitmap(page_bitmap.get(), 612, 792, kMultilineBackspaceMD5);