From 041cb248e818823caaaabc67db92b16499d0416d Mon Sep 17 00:00:00 2001
From: Vasiliy Telezhnikov <vasilyt@chromium.org>
Date: Thu, 02 Feb 2023 15:42:28 +0000
Subject: [PATCH] CHECK that passthrough command decoder is used on launched platforms

This CL adds enforces that validating command decoder is not used on
platforms where passthrough is fully launched. We still allow to use it
by tests on linux

Bug: 1406585
Change-Id: Id6bc1d748fdf9c953dde76c8d4b5f59ddef60857
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4212134
Reviewed-by: Kyle Charbonneau <kylechar@chromium.org>
Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1100440}
---

diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index eb710696..b22dffb 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -3447,7 +3447,13 @@
                                            outputter, group);
   }
 
+// Allow linux to run fuzzers.
+#if BUILDFLAG(ENABLE_VALIDATING_COMMAND_DECODER) || BUILDFLAG(IS_LINUX)
   return new GLES2DecoderImpl(client, command_buffer_service, outputter, group);
+#else
+  LOG(FATAL) << "Validating command decoder is not supported.";
+  return nullptr;
+#endif
 }
 
 GLES2DecoderImpl::GLES2DecoderImpl(
diff --git a/gpu/ipc/service/gpu_init.cc b/gpu/ipc/service/gpu_init.cc
index 40977d9b..50171e20 100644
--- a/gpu/ipc/service/gpu_init.cc
+++ b/gpu/ipc/service/gpu_init.cc
@@ -510,8 +510,9 @@
 
   auto impl = gl::GetGLImplementationParts();
   bool gl_disabled = impl == gl::kGLImplementationDisabled;
-  bool is_swangle = impl == gl::ANGLEImplementation::kSwiftShader;
 
+#if BUILDFLAG(ENABLE_VALIDATING_COMMAND_DECODER)
+  bool is_swangle = impl == gl::ANGLEImplementation::kSwiftShader;
   // Compute passthrough decoder status before ComputeGpuFeatureInfo below.
   // Do this after GL is initialized so extensions can be queried.
   // Using SwANGLE forces the passthrough command decoder.
@@ -533,6 +534,20 @@
   }
   gpu_preferences_.use_passthrough_cmd_decoder =
       gpu_info_.passthrough_cmd_decoder;
+#else
+  // If gl is disabled passthrough/validating command decoder doesn't matter. If
+  // it's not ensure that passthrough command decoder is supported as it's our
+  // only option.
+  if (!gl_disabled) {
+    LOG_IF(FATAL, !gles2::PassthroughCommandDecoderSupported())
+        << "Passthrough is not supported, GL is "
+        << gl::GetGLImplementationGLName(gl::GetGLImplementationParts())
+        << ", ANGLE is "
+        << gl::GetGLImplementationANGLEName(gl::GetGLImplementationParts());
+    gpu_info_.passthrough_cmd_decoder = true;
+    gpu_preferences_.use_passthrough_cmd_decoder = true;
+  }
+#endif
 
   // We need to collect GL strings (VENDOR, RENDERER) for blocklisting purposes.
   if (!gl_disabled) {