Implement easy GPU feature status summary.

content/common/gpu_feature_flags.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/gpu_feature_flags.h"
 
 #include "base/logging.h"
+#include "base/string_util.h"
+#include <vector>
 
 const char GpuFeatureFlags::kGpuFeatureNameAccelerated2dCanvas[] =
     "accelerated_2d_canvas";
 const char GpuFeatureFlags::kGpuFeatureNameAcceleratedCompositing[] =
     "accelerated_compositing";
 const char GpuFeatureFlags::kGpuFeatureNameWebgl[] = "webgl";
 const char GpuFeatureFlags::kGpuFeatureNameMultisampling[] = "multisampling";
 const char GpuFeatureFlags::kGpuFeatureNameAll[] = "all";
 
 GpuFeatureFlags::GpuFeatureFlags()
     : flags_(0) {
 }
 
 void GpuFeatureFlags::set_flags(uint32 flags) {
   DCHECK_EQ(flags & (~kGpuFeatureAll), 0u);
   flags_ = flags;
 }
 
 uint32 GpuFeatureFlags::flags() const {
   return flags_;
 }
 
 void GpuFeatureFlags::Combine(const GpuFeatureFlags& other) {
   flags_ |= other.flags_;
 }
 
+// static
 GpuFeatureFlags::GpuFeatureType GpuFeatureFlags::StringToGpuFeatureType(
     const std::string& feature_string) {
   if (feature_string == kGpuFeatureNameAccelerated2dCanvas)
     return kGpuFeatureAccelerated2dCanvas;
   else if (feature_string == kGpuFeatureNameAcceleratedCompositing)
     return kGpuFeatureAcceleratedCompositing;
   else if (feature_string == kGpuFeatureNameWebgl)
     return kGpuFeatureWebgl;
   else if (feature_string == kGpuFeatureNameMultisampling)
     return kGpuFeatureMultisampling;
   else if (feature_string == kGpuFeatureNameAll)
     return kGpuFeatureAll;
   return kGpuFeatureUnknown;
 }
 
+// static
+std::string GpuFeatureFlags::GpuFeatureTypeToUserFriendlyString(
+    GpuFeatureFlags::GpuFeatureType type) {
+  std::vector<std::string> matches;
+  if (type == kGpuFeatureAll) {
+    matches.push_back("All GPU features");

[zmo, 2011/04/07 20:46:06]

If you don't care about the difference between "accelerated_2d_canvas" and
"Accelerated 2D Canvas", maybe you can use the defined kGpuFeatureNameXXX here.

+  } else {
+    if (kGpuFeatureAccelerated2dCanvas & type)
+      matches.push_back("Accelerated 2D Canvas");
+    if (kGpuFeatureAcceleratedCompositing & type)
+      matches.push_back("Accelerated Compositing");
+    if (kGpuFeatureWebgl & type)
+      matches.push_back("WebGL");
+    if (kGpuFeatureMultisampling & type)
+      matches.push_back("WebGL + Canvas Multisampling");

[zmo, 2011/04/07 20:46:06]

I think only WebGL has Multisampling

+    if (!matches.size())
+      matches.push_back("Unknown feature");

[Avi (use Gerrit), 2011/04/07 00:28:20]

Gah. No, no, no. All user-visible text must go through internationalization and
strings.

+  }
+  return JoinString(matches, ',');

[zmo, 2011/04/07 20:46:06]

There is no loop here, so why do you need a vector and JoinString?

+}