[Impeller] Control GL error checking and tracing via GN options.

impeller/BUILD.gn

@@ -25,6 +25,14 @@ config("impeller_public_config") {
     defines += [ "IMPELLER_ENABLE_OPENGLES=1" ]
   }
 
+  if (impeller_trace_all_gl_calls) {
+    defines += [ "IMPELLER_TRACE_ALL_GL_CALLS" ]
+  }
+
+  if (impeller_error_check_all_gl_calls) {
+    defines += [ "IMPELLER_ERROR_CHECK_ALL_GL_CALLS" ]
+  }
+
   if (is_win) {
     defines += [
       "_USE_MATH_DEFINES",

impeller/renderer/backend/gles/proc_table_gles.h

@@ -11,6 +11,7 @@
 #include "flutter/fml/logging.h"
 #include "flutter/fml/macros.h"
 #include "flutter/fml/mapping.h"
+#include "flutter/fml/trace_event.h"
 #include "impeller/renderer/backend/gles/capabilities_gles.h"
 #include "impeller/renderer/backend/gles/description_gles.h"
 #include "impeller/renderer/backend/gles/gles.h"
@@ -64,7 +65,12 @@ struct GLProc {
   ///
   template <class... Args>
   auto operator()(Args&&... args) const {
+#ifdef IMPELLER_ERROR_CHECK_ALL_GL_CALLS
     AutoErrorCheck error(error_fn, name);
+#endif  // IMPELLER_ERROR_CHECK_ALL_GL_CALLS
+#ifdef IMPELLER_TRACE_ALL_GL_CALLS
+    TRACE_EVENT0("impeller", name);
+#endif  // IMPELLER_TRACE_ALL_GL_CALLS
     return function(std::forward<Args>(args)...);
   }
 

impeller/tools/impeller.gni

@@ -23,6 +23,13 @@ declare_args() {
   # If this is the empty string, impellerc will be built.
   # If it is non-empty, it should be the absolute path to impellerc.
   impeller_use_prebuilt_impellerc = ""
+
+  # If enabled, all OpenGL calls will be traced. Because additional trace
+  # overhead may be substantial, this is not enabled by default.
+  impeller_trace_all_gl_calls = false
+
+  # Call glGetError after each OpenGL call and log failures.
+  impeller_error_check_all_gl_calls = is_debug
 }
 
 declare_args() {