Use the non-thread-hostile FontProviderSyncPtr for font resolution. (#5105)

content_handler/application_runner.cc

@@ -108,13 +108,18 @@ void ApplicationRunner::SetupICU() {
 }
 
 void ApplicationRunner::SetupGlobalFonts() {
-  fonts::FontProviderPtr font_provider(
-      host_context_->ConnectToEnvironmentService<fonts::FontProvider>());
-  auto font_manager =
-      sk_make_sp<txt::FuchsiaFontManager>(std::move(font_provider));
-  blink::FontCollection::ForProcess()
-      .GetFontCollection()
-      ->SetDefaultFontManager(std::move(font_manager));
+  // Fuchsia does not have per application (shell) fonts. Instead, all fonts
+  // must be obtained from the font provider.
+  auto process_font_collection =
+      blink::FontCollection::ForProcess().GetFontCollection();
+
+  // Connect to the system font provider.
+  fonts::FontProviderSyncPtr sync_font_provider;
+  host_context_->ConnectToEnvironmentService(sync_font_provider.NewRequest());
+
+  // Set the default font manager.
+  process_font_collection->SetDefaultFontManager(
+      sk_make_sp<txt::FuchsiaFontManager>(std::move(sync_font_provider)));
 }
 
 void ApplicationRunner::FireTerminationCallbackIfNecessary() {

content_handler/fuchsia_font_manager.cc

@@ -54,7 +54,7 @@ fonts::FontSlant ToFontSlant(SkFontStyle::Slant slant) {
 
 }  // anonymous namespace
 
-FuchsiaFontManager::FuchsiaFontManager(fonts::FontProviderPtr provider)
+FuchsiaFontManager::FuchsiaFontManager(fonts::FontProviderSyncPtr provider)
     : font_provider_(std::move(provider)) {}
 
 FuchsiaFontManager::~FuchsiaFontManager() = default;
@@ -97,12 +97,7 @@ SkTypeface* FuchsiaFontManager::onMatchFamilyStyle(
   request.slant = ToFontSlant(style.slant());
 
   fonts::FontResponsePtr response;
-  font_provider_->GetFont(
-      std::move(request),
-      [&response](fonts::FontResponsePtr r) { response = std::move(r); });
-  font_provider_.WaitForResponse();
-
-  if (!response) {
+  if (!font_provider_->GetFont(std::move(request), &response)) {
     FXL_DLOG(ERROR) << "Unable to contact the font provider. Did you run "
                        "Flutter in an environment that has a font manager?";
     return nullptr;

content_handler/fuchsia_font_manager.h

@@ -17,8 +17,8 @@
 #ifndef TXT_FUCHSIA_FONT_MANAGER_H_
 #define TXT_FUCHSIA_FONT_MANAGER_H_
 
-#include <memory>
 #include <fuchsia/cpp/fonts.h>
+#include <memory>
 #include "lib/fxl/macros.h"
 #include "third_party/skia/include/core/SkStream.h"
 #include "third_party/skia/include/core/SkTypeface.h"
@@ -28,7 +28,7 @@ namespace txt {
 
 class FuchsiaFontManager final : public SkFontMgr {
  public:
-  FuchsiaFontManager(fonts::FontProviderPtr provider);
+  FuchsiaFontManager(fonts::FontProviderSyncPtr provider);
 
   ~FuchsiaFontManager() override;
 
@@ -81,7 +81,7 @@ class FuchsiaFontManager final : public SkFontMgr {
   FXL_DISALLOW_COPY_AND_ASSIGN(FuchsiaFontManager);
 
  private:
-  mutable fonts::FontProviderPtr font_provider_;
+  mutable fonts::FontProviderSyncPtr font_provider_;
 };
 
 }  // namespace txt