[Impeller] started std::moving Commands instead of copying (#44508)

Each Command is 440 B so copying them when adding them to the RenderPass adds up.  This change represents a 36% speedup in `TextContents::Render` when scrolling around on the main screen of the of the Flutter Gallery.

issue: flutter/flutter#131787

## before
<img width="1217" alt="Screenshot 2023-08-08 at 1 11 30 PM" src="https://github.com/flutter/engine/assets/30870216/3545f9cd-b596-4a7c-bcf0-a20c7f7c40e8">

## after

<img width="1048" alt="Screenshot 2023-08-08 at 1 10 05 PM" src="https://github.com/flutter/engine/assets/30870216/3443ec70-5d4f-4022-b3e7-41b13c25cb00">

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

Author: gaaclarke

impeller/entity/contents/checkerboard_contents.cc

@@ -49,7 +49,7 @@ bool CheckerboardContents::Render(const ContentContext& renderer,
   frag_info.square_size = square_size_;
   FS::BindFragInfo(cmd, host_buffer.EmplaceUniform(frag_info));
 
-  pass.AddCommand(cmd);
+  pass.AddCommand(std::move(cmd));
 
   return true;
 }

impeller/entity/contents/clip_contents.cc

@@ -107,7 +107,7 @@ bool ClipContents::Render(const ContentContext& renderer,
 
       options.primitive_type = PrimitiveType::kTriangleStrip;
       cmd.pipeline = renderer.GetClipPipeline(options);
-      pass.AddCommand(cmd);
+      pass.AddCommand(Command(cmd));
     }
 
     {

impeller/entity/contents/filters/blend_filter_contents.cc

@@ -180,7 +180,7 @@ static std::optional<Entity> AdvancedBlend(
 
     auto uniform_view = host_buffer.EmplaceUniform(frame_info);
     VS::BindFrameInfo(cmd, uniform_view);
-    pass.AddCommand(cmd);
+    pass.AddCommand(std::move(cmd));
 
     return true;
   };
@@ -336,7 +336,7 @@ std::optional<Entity> BlendFilterContents::CreateForegroundAdvancedBlend(
     auto uniform_view = host_buffer.EmplaceUniform(frame_info);
     VS::BindFrameInfo(cmd, uniform_view);
 
-    return pass.AddCommand(cmd);
+    return pass.AddCommand(std::move(cmd));
   };
   CoverageProc coverage_proc =
       [coverage](const Entity& entity) -> std::optional<Rect> {
@@ -476,7 +476,7 @@ std::optional<Entity> BlendFilterContents::CreateForegroundPorterDuffBlend(
     auto uniform_view = host_buffer.EmplaceUniform(frame_info);
     VS::BindFrameInfo(cmd, uniform_view);
 
-    return pass.AddCommand(cmd);
+    return pass.AddCommand(std::move(cmd));
   };
 
   CoverageProc coverage_proc =
@@ -573,7 +573,7 @@ static std::optional<Entity> PipelineBlend(
       FS::BindFragInfo(cmd, host_buffer.EmplaceUniform(frag_info));
       VS::BindFrameInfo(cmd, host_buffer.EmplaceUniform(frame_info));
 
-      pass.AddCommand(cmd);
+      pass.AddCommand(std::move(cmd));
       return true;
     };
 

impeller/entity/contents/filters/gaussian_blur_filter_contents.cc

@@ -303,7 +303,7 @@ std::optional<Entity> DirectionalGaussianBlurFilterContents::RenderFilter(
       FS::BindMaskInfo(cmd, host_buffer.EmplaceUniform(mask_info));
     }
 
-    return pass.AddCommand(cmd);
+    return pass.AddCommand(std::move(cmd));
   };
 
   Vector2 scale;

impeller/entity/contents/filters/morphology_filter_contents.cc

@@ -135,7 +135,7 @@ std::optional<Entity> DirectionalMorphologyFilterContents::RenderFilter(
     VS::BindFrameInfo(cmd, host_buffer.EmplaceUniform(frame_info));
     FS::BindFragInfo(cmd, host_buffer.EmplaceUniform(frag_info));
 
-    return pass.AddCommand(cmd);
+    return pass.AddCommand(std::move(cmd));
   };
 
   auto out_texture = renderer.MakeSubpass("Directional Morphology Filter",

impeller/entity/contents/framebuffer_blend_contents.cc

@@ -154,7 +154,7 @@ bool FramebufferBlendContents::Render(const ContentContext& renderer,
   frag_info.src_input_alpha = src_snapshot->opacity;
   FS::BindFragInfo(cmd, host_buffer.EmplaceUniform(frag_info));
 
-  return pass.AddCommand(cmd);
+  return pass.AddCommand(std::move(cmd));
 }
 
 }  // namespace impeller

impeller/entity/contents/text_contents.cc

@@ -212,7 +212,7 @@ bool TextContents::Render(const ContentContext& renderer,
       .index_type = IndexType::kNone,
   });
 
-  return pass.AddCommand(cmd);
+  return pass.AddCommand(std::move(cmd));
 }
 
 }  // namespace impeller

impeller/renderer/render_pass.cc

@@ -43,7 +43,7 @@ void RenderPass::SetLabel(std::string label) {
   OnSetLabel(std::move(label));
 }
 
-bool RenderPass::AddCommand(Command command) {
+bool RenderPass::AddCommand(Command&& command) {
   if (!command) {
     VALIDATION_LOG << "Attempted to add an invalid command to the render pass.";
     return false;

impeller/renderer/render_pass.h

@@ -47,7 +47,7 @@ class RenderPass {
   ///
   /// @return     If the command was valid for subsequent commitment.
   ///
-  bool AddCommand(Command command);
+  bool AddCommand(Command&& command);
 
   //----------------------------------------------------------------------------
   /// @brief      Encode the recorded commands to the underlying command buffer.

impeller/renderer/renderer_unittests.cc

@@ -270,7 +270,7 @@ TEST_P(RendererTest, CanRenderMultiplePrimitives) {
                        Matrix::MakeTranslation({i * 50.0f, j * 50.0f, 0.0f});
         VS::BindUniformBuffer(
             cmd, pass.GetTransientsBuffer().EmplaceUniform(uniforms));
-        if (!pass.AddCommand(cmd)) {
+        if (!pass.AddCommand(std::move(cmd))) {
           return false;
         }
       }
@@ -445,7 +445,7 @@ TEST_P(RendererTest, CanRenderInstanced) {
     cmd.BindVertices(builder.CreateVertexBuffer(pass.GetTransientsBuffer()));
 
     cmd.instance_count = kInstancesCount;
-    pass.AddCommand(cmd);
+    pass.AddCommand(std::move(cmd));
     return true;
   }));
 }
@@ -863,7 +863,7 @@ TEST_P(RendererTest, TheImpeller) {
     FS::BindBlueNoise(cmd, blue_noise, noise_sampler);
     FS::BindCubeMap(cmd, cube_map, cube_map_sampler);
 
-    pass.AddCommand(cmd);
+    pass.AddCommand(std::move(cmd));
     return true;
   };
   OpenPlaygroundHere(callback);
@@ -919,7 +919,7 @@ TEST_P(RendererTest, ArrayUniforms) {
     FS::BindFragInfo(cmd,
                      pass.GetTransientsBuffer().EmplaceUniform(fs_uniform));
 
-    pass.AddCommand(cmd);
+    pass.AddCommand(std::move(cmd));
     return true;
   };
   OpenPlaygroundHere(callback);
@@ -964,7 +964,7 @@ TEST_P(RendererTest, InactiveUniforms) {
     FS::BindFragInfo(cmd,
                      pass.GetTransientsBuffer().EmplaceUniform(fs_uniform));
 
-    pass.AddCommand(cmd);
+    pass.AddCommand(std::move(cmd));
     return true;
   };
   OpenPlaygroundHere(callback);