Make gpu black list work again on Linux

content/browser/devtools/protocol/system_info_handler.cc

Index: content/browser/devtools/protocol/system_info_handler.cc
diff --git a/content/browser/devtools/protocol/system_info_handler.cc b/content/browser/devtools/protocol/system_info_handler.cc
index 27877b0bd981f9fd9d43169fdc261953642d22e8..340bca475580c466412c82c40a82cd54407f7c9e 100644
--- a/content/browser/devtools/protocol/system_info_handler.cc
+++ b/content/browser/devtools/protocol/system_info_handler.cc
@@ -8,9 +8,12 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "content/browser/gpu/compositor_util.h"
 #include "content/public/browser/gpu_data_manager.h"
+#include "gpu/config/gpu_feature_type.h"
 #include "gpu/config/gpu_info.h"
+#include "gpu/config/gpu_switches.h"
 
 namespace content {
 namespace devtools {
@@ -147,9 +150,22 @@ void SystemInfoHandler::SetClient(scoped_ptr<Client> client) {
 }
 
 Response SystemInfoHandler::GetInfo(DevToolsCommandId command_id) {
+  bool skip_request_collection = false;
+#if defined(OS_LINUX)
+  skip_request_collection = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kGpuTestingNoCompleteInfoCollection);
+  for (int feature = 0; feature < gpu::NUMBER_OF_GPU_FEATURE_TYPES; ++feature) {

[Zhenyao Mo, 2016/02/02 22:22:34]

I don't think this for-loop logic is necessary.  It's too tuned to the test.
Also, you don't need to limit the commandline switch to linux.  Semantically
when it's passed it, it should be honored everywhere.

Also, you should also honor this commandline switch in
gpu_data_manager_impl_private.cc.  Even it's not making a difference for this
CL's test, it's better we make it always semantically correct, so no confusion
and surprise in the future.

+    skip_request_collection &=
+        GpuDataManager::GetInstance()->IsFeatureBlacklisted(feature);
+    if (!skip_request_collection)
+      break;
+  }
+#endif
+
   std::string reason;
   if (!GpuDataManager::GetInstance()->GpuAccessAllowed(&reason) ||
-      GpuDataManager::GetInstance()->IsEssentialGpuInfoAvailable()) {
+      GpuDataManager::GetInstance()->IsEssentialGpuInfoAvailable() ||
+      skip_request_collection) {
     // The GpuDataManager already has all of the information needed to make
     // GPU-based blacklisting decisions. Post a task to give it to the
     // client asynchronously.