blink fonts: Load Android SkFontMgr on Linux.

content/zygote/zygote_main_linux.cc

Index: content/zygote/zygote_main_linux.cc
diff --git a/content/zygote/zygote_main_linux.cc b/content/zygote/zygote_main_linux.cc
index c30e1084a92c6eecaf07417f30c3d5464b9b0f8a..37314abed831b35e91101ddc18ea3b2382fe39c4 100644
--- a/content/zygote/zygote_main_linux.cc
+++ b/content/zygote/zygote_main_linux.cc
@@ -46,6 +46,7 @@
 #include "sandbox/linux/services/namespace_sandbox.h"
 #include "sandbox/linux/services/thread_helpers.h"
 #include "sandbox/linux/suid/client/setuid_sandbox_client.h"
+#include "third_party/WebKit/public/web/linux/WebFontRendering.h"
 #include "third_party/icu/source/i18n/unicode/timezone.h"
 #include "third_party/skia/include/ports/SkFontConfigInterface.h"
 
@@ -67,6 +68,8 @@
 #include <sanitizer/coverage_interface.h>
 #endif
 
+#include "third_party/skia/include/ports/SkFontMgr_android.h"
+
 namespace content {
 
 namespace {
@@ -344,8 +347,32 @@ static void ZygotePreSandboxInit() {
 #if defined(ENABLE_WEBRTC)
   InitializeWebRtcModule();
 #endif
+
   SkFontConfigInterface::SetGlobal(
       new FontConfigIPC(GetSandboxFD()))->unref();
+
+  // Set the android SkFontMgr for blink. We need to ensure this is done
+  // before the sandbox is initialized to allow the font manager to access
+  // font configuration files on disk.
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kAndroidFontsLocation)) {
+    std::string android_fonts_dir =
+        base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+            switches::kAndroidFontsLocation);
+
+    if (android_fonts_dir.size() > 0 && android_fonts_dir.back() != '/')
+      android_fonts_dir += '/';
+    std::string font_config = android_fonts_dir + "fonts.xml";
+    SkFontMgr_Android_CustomFonts custom = {
+        SkFontMgr_Android_CustomFonts::SystemFontUse::kOnlyCustom,
+        android_fonts_dir.c_str(),
+        font_config.c_str(),
+        nullptr,
+        true,
+    };
+
+    blink::WebFontRendering::setSkiaFontManager(SkFontMgr_New_Android(&custom));
+  }
 }
 
 static bool CreateInitProcessReaper(base::Closure* post_fork_parent_callback) {