Make {flow|fml|impeller}/... compatible with .clang_tidy. (#48241)

Another few stragglers.

Author: matanlurey

flow/testing/mock_layer.h

@@ -27,13 +27,13 @@ class MockLayer : public Layer {
  public:
   explicit MockLayer(const SkPath& path, DlPaint paint = DlPaint());
 
-  static std::shared_ptr<MockLayer> Make(SkPath path,
+  static std::shared_ptr<MockLayer> Make(const SkPath& path,
                                          DlPaint paint = DlPaint()) {
-    return std::make_shared<MockLayer>(std::move(path), std::move(paint));
+    return std::make_shared<MockLayer>(path, std::move(paint));
   }
 
-  static std::shared_ptr<MockLayer> MakeOpacityCompatible(SkPath path) {
-    auto mock_layer = std::make_shared<MockLayer>(std::move(path), DlPaint());
+  static std::shared_ptr<MockLayer> MakeOpacityCompatible(const SkPath& path) {
+    auto mock_layer = std::make_shared<MockLayer>(path, DlPaint());
     mock_layer->set_fake_opacity_compatible(true);
     return mock_layer;
   }

fml/platform/linux/message_loop_linux.cc

@@ -16,8 +16,7 @@ static constexpr int kClockType = CLOCK_MONOTONIC;
 
 MessageLoopLinux::MessageLoopLinux()
     : epoll_fd_(FML_HANDLE_EINTR(::epoll_create(1 /* unused */))),
-      timer_fd_(::timerfd_create(kClockType, TFD_NONBLOCK | TFD_CLOEXEC)),
-      running_(false) {
+      timer_fd_(::timerfd_create(kClockType, TFD_NONBLOCK | TFD_CLOEXEC)) {
   FML_CHECK(epoll_fd_.is_valid());
   FML_CHECK(timer_fd_.is_valid());
   bool added_source = AddOrRemoveTimerSource(true);

fml/platform/linux/message_loop_linux.h

@@ -17,7 +17,7 @@ class MessageLoopLinux : public MessageLoopImpl {
  private:
   fml::UniqueFD epoll_fd_;
   fml::UniqueFD timer_fd_;
-  bool running_;
+  bool running_ = false;
 
   MessageLoopLinux();
 

impeller/renderer/backend/gles/handle_gles.h

@@ -78,7 +78,11 @@ inline std::ostream& operator<<(std::ostream& out,
   if (handle.IsDead()) {
     out << "DEAD";
   } else {
-    out << handle.name.value().id;
+    if (handle.name.has_value()) {
+      out << handle.name.value().id;
+    } else {
+      out << "UNNAMED";
+    }
   }
   out << ")";
   return out;

impeller/renderer/backend/gles/sampler_gles.h

@@ -25,7 +25,7 @@ class SamplerGLES final : public Sampler,
  private:
   friend class SamplerLibraryGLES;
 
-  SamplerGLES(SamplerDescriptor desc);
+  explicit SamplerGLES(SamplerDescriptor desc);
 
   // |Sampler|
   bool IsValid() const override;