Handle all context lost reasons when determining guilt of domain.

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index 8764010907cea33a8f5ed6bed108fd07ab166d0a..8727e61632ee8cffd2e5c80ec803cc53dd3f61e2 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -879,19 +879,25 @@ void GpuProcessHost::OnDidLoseContext(bool offscreen,
     return;
   }
 
-  GpuDataManagerImpl::DomainGuilt guilt;
+  GpuDataManagerImpl::DomainGuilt guilt =
+      GpuDataManagerImpl::DOMAIN_GUILT_UNKNOWN;
   switch (reason) {
     case gpu::error::kGuilty:
       guilt = GpuDataManagerImpl::DOMAIN_GUILT_KNOWN;
       break;
+    // Treat most other error codes as though they had unknown provenance.
+    // In practice this doesn't affect the user experience. A lost context
+    // of either known or unknown guilt still causes user-level 3D APIs
+    // (e.g. WebGL) to be blocked on that domain until the user manually
+    // reenables them.
     case gpu::error::kUnknown:
-      guilt = GpuDataManagerImpl::DOMAIN_GUILT_UNKNOWN;
+    case gpu::error::kOutOfMemory:
+    case gpu::error::kMakeCurrentFailed:
+    case gpu::error::kGpuChannelLost:
+    case gpu::error::kInvalidGpuMessage:
       break;
     case gpu::error::kInnocent:
       return;
-    default:
-      NOTREACHED();
-      return;
   }
 
   GpuDataManagerImpl::GetInstance()->BlockDomainFrom3DAPIs(url, guilt);