Fix code review issue

1.Rename static veriable(nextTextureId -> kNextTextureId)
2.Modify comment, make it more clear.
3.Rename function name(FlutterDesktopDestructionCallback)

Author: xiaowei-guan

shell/platform/common/cpp/public/flutter_texture_registrar.h

@@ -67,7 +67,7 @@ typedef const FlutterDesktopGpuBuffer* (
                                              size_t height,
                                              void* user_data);
 
-typedef void (*FlutterDesktopDestructionCallback)(void* user_data);
+typedef void (*FlutterDesktopGpuBufferDestructionCallback)(void* user_data);
 
 // An object used to configure pixel buffer textures.
 typedef struct {
@@ -79,10 +79,10 @@ typedef struct {
 
 // An object used to configure GPU buffer textures.
 typedef struct {
-  // The callback used by the engine to copy the GPU buffer object.
+  // The callback used by the engine to obtain the GPU buffer object.
   FlutterDesktopGpuBufferTextureCallback callback;
-  // The callback used by the engine to desturction GPU buffer object.
-  FlutterDesktopDestructionCallback destruction_callback;
+  // The callback used by the engine to destruct GPU buffer object.
+  FlutterDesktopGpuBufferDestructionCallback destruction_callback;
   // Opaque data that will get passed to the provided |callback|.
   void* user_data;
 } FlutterDesktopGPUBufferTextureConfig;

shell/platform/tizen/external_texture.h

@@ -29,14 +29,14 @@ struct ExternalTextureGLState {
   GLuint gl_texture;
 };
 
-static std::atomic_long nextTextureId = {1};
+static std::atomic_long kNextTextureId = {1};
 
 // An adaptation class of flutter engine and external texture interface.
 class ExternalTexture : public std::enable_shared_from_this<ExternalTexture> {
  public:
   ExternalTexture()
       : state_(std::make_unique<ExternalTextureGLState>()),
-        texture_id_(nextTextureId++) {}
+        texture_id_(kNextTextureId++) {}
   virtual ~ExternalTexture() = default;
 
   /**

shell/platform/tizen/external_texture_surface_gl.cc

@@ -37,7 +37,7 @@ static void OnCollectTexture(void* textureGL) {
 
 ExternalTextureSurfaceGL::ExternalTextureSurfaceGL(
     FlutterDesktopGpuBufferTextureCallback texture_callback,
-    FlutterDesktopDestructionCallback destruction_callback,
+    FlutterDesktopGpuBufferDestructionCallback destruction_callback,
     void* user_data)
     : ExternalTexture(),
       texture_callback_(texture_callback),

shell/platform/tizen/external_texture_surface_gl.h

@@ -14,7 +14,7 @@ class ExternalTextureSurfaceGL : public ExternalTexture {
  public:
   ExternalTextureSurfaceGL(
       FlutterDesktopGpuBufferTextureCallback texture_callback,
-      FlutterDesktopDestructionCallback destruction_callback,
+      FlutterDesktopGpuBufferDestructionCallback destruction_callback,
       void* user_data);
 
   virtual ~ExternalTextureSurfaceGL();
@@ -34,7 +34,7 @@ class ExternalTextureSurfaceGL : public ExternalTexture {
 
  private:
   FlutterDesktopGpuBufferTextureCallback texture_callback_ = nullptr;
-  FlutterDesktopDestructionCallback destruction_callback_ = nullptr;
+  FlutterDesktopGpuBufferDestructionCallback destruction_callback_ = nullptr;
   void* user_data_ = nullptr;
 };