[engine] dont double free surface texture interop objects. (#170284)

Fixes https://github.com/flutter/flutter/issues/152459

I suspect the double free is related to
https://github.com/flutter/flutter/issues/162147 .

With the Impeller backend, the second free is performed by the reactor
and comes only after the application has returned to the foreground.
This increaases the likelyhood that we nuke a handle that is in active
use by another part of the system.

Since SurfaceTexture:: detachFromGLContext is documented as releasing
the texture, we don't need to free it at all and can "leak" it on our
side.

engine/src/flutter/impeller/renderer/backend/gles/reactor_gles.cc

@@ -233,6 +233,9 @@ HandleGLES ReactorGLES::CreateHandle(HandleType type, GLuint external_handle) {
 }
 
 void ReactorGLES::CollectHandle(HandleGLES handle) {
+  if (handle.IsDead()) {
+    return;
+  }
   if (handle.untracked_id_.has_value()) {
     LiveHandle live_handle(GLStorage{.integer = handle.untracked_id_.value()});
     live_handle.pending_collection = true;

engine/src/flutter/impeller/renderer/backend/gles/test/texture_gles_unittests.cc

@@ -7,6 +7,7 @@
 #include "flutter/impeller/renderer/backend/gles/texture_gles.h"
 #include "flutter/testing/testing.h"
 #include "gtest/gtest.h"
+#include "impeller/base/validation.h"
 #include "impeller/core/formats.h"
 #include "impeller/core/texture_descriptor.h"
 #include "impeller/renderer/backend/gles/handle_gles.h"
@@ -93,4 +94,26 @@ TEST_P(TextureGLESTest, Binds2DTexture) {
   }
 }
 
+TEST_P(TextureGLESTest, Leak) {
+  TextureDescriptor desc;
+  desc.storage_mode = StorageMode::kDevicePrivate;
+  desc.size = {100, 100};
+  desc.format = PixelFormat::kR8G8B8A8UNormInt;
+  desc.type = TextureType::kTexture2D;
+  desc.sample_count = SampleCount::kCount1;
+
+  auto texture = GetContext()->GetResourceAllocator()->CreateTexture(desc);
+
+  ASSERT_TRUE(texture);
+
+  std::optional<GLuint> handle = TextureGLES::Cast(*texture).GetGLHandle();
+  EXPECT_TRUE(handle.has_value());
+
+  TextureGLES::Cast(*texture).Leak();
+
+  ScopedValidationDisable disable_validation;
+  handle = TextureGLES::Cast(*texture).GetGLHandle();
+  EXPECT_FALSE(handle.has_value());
+}
+
 }  // namespace impeller::testing

engine/src/flutter/impeller/renderer/backend/gles/texture_gles.cc

@@ -16,6 +16,7 @@
 #include "impeller/core/formats.h"
 #include "impeller/core/texture_descriptor.h"
 #include "impeller/renderer/backend/gles/formats_gles.h"
+#include "impeller/renderer/backend/gles/handle_gles.h"
 
 namespace impeller {
 
@@ -229,6 +230,10 @@ TextureGLES::~TextureGLES() {
   }
 }
 
+void TextureGLES::Leak() {
+  handle_ = HandleGLES::DeadHandle();
+}
+
 // |Texture|
 bool TextureGLES::IsValid() const {
   return is_valid_;

engine/src/flutter/impeller/renderer/backend/gles/texture_gles.h

@@ -102,6 +102,10 @@ class TextureGLES final : public Texture,
 
   bool IsWrapped() const;
 
+  /// @brief Reset the internal texture state so that the reactor will not free
+  ///        the associated handle.
+  void Leak();
+
   std::optional<GLuint> GetFBO() const;
 
   //----------------------------------------------------------------------------

engine/src/flutter/shell/platform/android/surface_texture_external_texture_gl_impeller.cc

@@ -55,6 +55,9 @@ void SurfaceTextureExternalTextureGLImpeller::ProcessFrame(
 
 void SurfaceTextureExternalTextureGLImpeller::Detach() {
   SurfaceTextureExternalTexture::Detach();
+  // Detach will collect the texture handle.
+  // See also: https://github.com/flutter/flutter/issues/152459
+  texture_->Leak();
   texture_.reset();
 }
 

engine/src/flutter/shell/platform/android/surface_texture_external_texture_gl_skia.cc

@@ -52,10 +52,9 @@ void SurfaceTextureExternalTextureGLSkia::ProcessFrame(PaintContext& context,
 
 void SurfaceTextureExternalTextureGLSkia::Detach() {
   SurfaceTextureExternalTexture::Detach();
-  if (texture_name_ != 0) {
-    glDeleteTextures(1, &texture_name_);
-    texture_name_ = 0;
-  }
+  // Detach will collect the texture handle.
+  // See also: https://github.com/flutter/flutter/issues/152459
+  texture_name_ = 0;
 }
 
 }  // namespace flutter