Fix incorrect texture format with OpenGL ES

Author: huanghongxun

shell/platform/linux/fl_backing_store_provider.cc

@@ -78,7 +78,11 @@ uint32_t fl_backing_store_provider_get_gl_target(FlBackingStoreProvider* self) {
 }
 
 uint32_t fl_backing_store_provider_get_gl_format(FlBackingStoreProvider* self) {
-  return GL_RGBA8;
+  if (epoxy_is_desktop_gl()) {
+    return GL_RGBA8;
+  } else {
+    return GL_BGRA8_EXT;
+  }
 }
 
 GdkRectangle fl_backing_store_provider_get_geometry(

shell/platform/linux/fl_renderer_gl.cc

@@ -61,6 +61,9 @@ static gboolean fl_renderer_gl_create_backing_store(
   backing_store_out->open_gl.framebuffer.user_data = provider;
   backing_store_out->open_gl.framebuffer.name = name;
   backing_store_out->open_gl.framebuffer.target = format;
+  backing_store_out->open_gl.framebuffer.destruction_callback = [](void* p) {
+    // backing store is destroyed in fl_renderer_gl_collect_backing_store ().
+  };
 
   return TRUE;
 }

shell/platform/linux/testing/mock_epoxy.cc

@@ -374,6 +374,18 @@ static void _glTexImage2D(GLenum target,
                           GLenum type,
                           const void* pixels) {}
 
+bool epoxy_has_gl_extension(const char* extension) {
+  return false;
+}
+
+bool epoxy_is_desktop_gl(void) {
+  return false;
+}
+
+int epoxy_gl_version(void) {
+  return 0;
+}
+
 #ifdef __GNUC__
 #define CONSTRUCT(_func) static void _func(void) __attribute__((constructor));
 #define DESTRUCT(_func) static void _func(void) __attribute__((destructor));