Maintain a FontCollection for each engine instance instead of a proce…

…ss-wide singleton (flutter#5521)

lib/ui/BUILD.gn

@@ -96,7 +96,6 @@ source_set("ui") {
     "$flutter_root/fml",
     "$flutter_root/glue",
     "$flutter_root/runtime:test_font",
-    "$flutter_root/third_party/txt",
     "//third_party/dart/runtime/bin:embedded_dart_io",
     "//third_party/rapidjson",
     "//third_party/skia",
@@ -107,4 +106,6 @@ source_set("ui") {
   if (is_fuchsia) {
     deps += [ "//topaz/public/dart-pkg/zircon" ]
   }
+
+  public_deps = ["$flutter_root/third_party/txt"]
 }

lib/ui/text/font_collection.cc

@@ -16,13 +16,6 @@
 
 namespace blink {
 
-FontCollection& FontCollection::ForProcess() {
-  static std::once_flag once = {};
-  static FontCollection* gCollection = nullptr;
-  std::call_once(once, []() { gCollection = new FontCollection(); });
-  return *gCollection;
-}
-
 FontCollection::FontCollection()
     : collection_(std::make_shared<txt::FontCollection>()) {
   collection_->SetDefaultFontManager(SkFontMgr::RefDefault());

lib/ui/text/font_collection.h

@@ -17,7 +17,9 @@ namespace blink {
 
 class FontCollection {
  public:
-  static FontCollection& ForProcess();
+  FontCollection();
+
+  ~FontCollection();
 
   std::shared_ptr<txt::FontCollection> GetFontCollection() const;
 
@@ -28,10 +30,6 @@ class FontCollection {
  private:
   std::shared_ptr<txt::FontCollection> collection_;
 
-  FontCollection();
-
-  ~FontCollection();
-
   FXL_DISALLOW_COPY_AND_ASSIGN(FontCollection);
 };
 

lib/ui/text/paragraph_builder.cc

@@ -8,6 +8,7 @@
 #include "flutter/common/task_runners.h"
 #include "flutter/lib/ui/text/font_collection.h"
 #include "flutter/lib/ui/ui_dart_state.h"
+#include "flutter/lib/ui/window/window.h"
 #include "flutter/third_party/txt/src/txt/font_style.h"
 #include "flutter/third_party/txt/src/txt/font_weight.h"
 #include "flutter/third_party/txt/src/txt/paragraph_style.h"
@@ -110,8 +111,8 @@ fxl::RefPtr<ParagraphBuilder> ParagraphBuilder::create(
     double lineHeight,
     const std::u16string& ellipsis,
     const std::string& locale) {
-  return fxl::MakeRefCounted<ParagraphBuilder>(
-      encoded, fontFamily, fontSize, lineHeight, ellipsis, locale);
+  return fxl::MakeRefCounted<ParagraphBuilder>(encoded, fontFamily, fontSize,
+                                               lineHeight, ellipsis, locale);
 }
 
 ParagraphBuilder::ParagraphBuilder(tonic::Int32List& encoded,
@@ -155,8 +156,10 @@ ParagraphBuilder::ParagraphBuilder(tonic::Int32List& encoded,
     style.locale = locale;
   }
 
+  FontCollection& font_collection =
+      UIDartState::Current()->window()->client()->GetFontCollection();
   m_paragraphBuilder = std::make_unique<txt::ParagraphBuilder>(
-      style, blink::FontCollection::ForProcess().GetFontCollection());
+      style, font_collection.GetFontCollection());
 }  // namespace blink
 
 ParagraphBuilder::~ParagraphBuilder() = default;
@@ -207,8 +210,7 @@ void ParagraphBuilder::pushStyle(tonic::Int32List& encoded,
           static_cast<txt::FontWeight>(encoded[tsFontWeightIndex]);
 
     if (mask & tsFontStyleMask)
-      style.font_style =
-          static_cast<txt::FontStyle>(encoded[tsFontStyleIndex]);
+      style.font_style = static_cast<txt::FontStyle>(encoded[tsFontStyleIndex]);
 
     if (mask & tsFontFamilyMask)
       style.font_family = fontFamily;

lib/ui/window/window.h

@@ -20,6 +20,7 @@ class DartLibraryNatives;
 }  // namespace tonic
 
 namespace blink {
+class FontCollection;
 class Scene;
 
 Dart_Handle ToByteData(const std::vector<uint8_t>& buffer);
@@ -31,6 +32,7 @@ class WindowClient {
   virtual void Render(Scene* scene) = 0;
   virtual void UpdateSemantics(SemanticsUpdate* update) = 0;
   virtual void HandlePlatformMessage(fxl::RefPtr<PlatformMessage> message) = 0;
+  virtual FontCollection& GetFontCollection() = 0;
 
  protected:
   virtual ~WindowClient();

runtime/runtime_controller.cc

@@ -249,6 +249,10 @@ void RuntimeController::HandlePlatformMessage(
   client_.HandlePlatformMessage(std::move(message));
 }
 
+FontCollection& RuntimeController::GetFontCollection() {
+  return client_.GetFontCollection();
+}
+
 Dart_Port RuntimeController::GetMainPort() {
   return root_isolate_ ? root_isolate_->main_port() : ILLEGAL_PORT;
 }

runtime/runtime_controller.h

@@ -10,6 +10,7 @@
 #include "flutter/common/task_runners.h"
 #include "flutter/flow/layers/layer_tree.h"
 #include "flutter/lib/ui/ui_dart_state.h"
+#include "flutter/lib/ui/text/font_collection.h"
 #include "flutter/lib/ui/window/pointer_data_packet.h"
 #include "flutter/lib/ui/window/window.h"
 #include "flutter/runtime/dart_vm.h"
@@ -124,6 +125,9 @@ class RuntimeController final : public WindowClient {
   // |blink::WindowClient|
   void HandlePlatformMessage(fxl::RefPtr<PlatformMessage> message) override;
 
+  // |blink::WindowClient|
+  FontCollection& GetFontCollection() override;
+
   FXL_DISALLOW_COPY_AND_ASSIGN(RuntimeController);
 };
 

runtime/runtime_delegate.h

@@ -10,6 +10,7 @@
 
 #include "flutter/flow/layers/layer_tree.h"
 #include "flutter/lib/ui/semantics/semantics_node.h"
+#include "flutter/lib/ui/text/font_collection.h"
 #include "flutter/lib/ui/window/platform_message.h"
 #include "third_party/dart/runtime/include/dart_api.h"
 
@@ -27,6 +28,8 @@ class RuntimeDelegate {
 
   virtual void HandlePlatformMessage(fxl::RefPtr<PlatformMessage> message) = 0;
 
+  virtual FontCollection& GetFontCollection() = 0;
+
  protected:
   virtual ~RuntimeDelegate();
 };

shell/common/BUILD.gn

@@ -100,7 +100,6 @@ source_set("common") {
     "$flutter_root/lib/ui",
     "$flutter_root/runtime",
     "$flutter_root/synchronization",
-    "$flutter_root/third_party/txt",
     "//garnet/public/lib/fxl",
     "//third_party/dart/runtime:dart_api",
     "//third_party/rapidjson",
@@ -109,6 +108,7 @@ source_set("common") {
   ]
 
   public_deps = [
+    "$flutter_root/third_party/txt",
     "//topaz/lib/tonic",
   ]
 

shell/common/engine.cc

@@ -87,9 +87,9 @@ bool Engine::UpdateAssetManager(
 
   // Using libTXT as the text engine.
   if (settings_.use_test_fonts) {
-    blink::FontCollection::ForProcess().RegisterTestFonts();
+    font_collection_.RegisterTestFonts();
   } else {
-    blink::FontCollection::ForProcess().RegisterFonts(*asset_manager_.get());
+    font_collection_.RegisterFonts(*asset_manager_.get());
   }
 
   return true;
@@ -377,6 +377,10 @@ void Engine::HandlePlatformMessage(
   }
 }
 
+blink::FontCollection& Engine::GetFontCollection() {
+  return font_collection_;
+}
+
 void Engine::HandleAssetPlatformMessage(
     fxl::RefPtr<blink::PlatformMessage> message) {
   fxl::RefPtr<blink::PlatformMessageResponse> response = message->response();

shell/common/engine.h

@@ -11,6 +11,7 @@
 #include "flutter/assets/asset_manager.h"
 #include "flutter/common/task_runners.h"
 #include "flutter/lib/ui/semantics/semantics_node.h"
+#include "flutter/lib/ui/text/font_collection.h"
 #include "flutter/lib/ui/window/platform_message.h"
 #include "flutter/lib/ui/window/viewport_metrics.h"
 #include "flutter/runtime/dart_vm.h"
@@ -109,6 +110,7 @@ class Engine final : public blink::RuntimeDelegate {
   fml::RefPtr<blink::AssetManager> asset_manager_;
   bool activity_running_;
   bool have_surface_;
+  blink::FontCollection font_collection_;
   fml::WeakPtrFactory<Engine> weak_factory_;
 
   // |blink::RuntimeDelegate|
@@ -124,6 +126,9 @@ class Engine final : public blink::RuntimeDelegate {
   void HandlePlatformMessage(
       fxl::RefPtr<blink::PlatformMessage> message) override;
 
+  // |blink::RuntimeDelegate|
+  blink::FontCollection& GetFontCollection() override;
+
   void StopAnimator();
 
   void StartAnimatorIfPossible();