Expose WebGL extension WEBGL_debug_renderer_info to Google domains

content/browser/gpu/gpu_data_manager_impl_private.cc

 // Copyright (c) 2013 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/browser/gpu/gpu_data_manager_impl_private.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/version.h"
 #include "cc/base/switches.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/gpu_data_manager_observer.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/config/gpu_control_list_jsons.h"
 #include "gpu/config/gpu_driver_bug_workaround_type.h"
 #include "gpu/config/gpu_feature_type.h"
 #include "gpu/config/gpu_info_collector.h"
 #include "gpu/config/gpu_util.h"
@@ skipping 273 matching lines @@
 const int kNumResetsWithinDuration = 1;
 
 // Enums for UMA histograms.
 enum BlockStatusHistogram {
   BLOCK_STATUS_NOT_BLOCKED,
   BLOCK_STATUS_SPECIFIC_DOMAIN_BLOCKED,
   BLOCK_STATUS_ALL_DOMAINS_BLOCKED,
   BLOCK_STATUS_MAX
 };
 
+bool IsWebGLDebugRendererInfoFieldTrialEnabled() {
+  const char kWebGLDebugRendererInfoFieldTrialName[] = "WebGLDebugRendererInfo";
+  const char kWebGLDebugRendererInfoFieldTrialEnabledName[] = "enabled";
+
+  base::FieldTrial* trial = base::FieldTrialList::Find(
+      kWebGLDebugRendererInfoFieldTrialName);
+  if (!trial)
+    return false;
+  return trial->group_name() == kWebGLDebugRendererInfoFieldTrialEnabledName;

[Alexei Svitkine (slow), 2013/10/30 18:10:18]

Instead, just use base::FieldTrialList::FindFullName() and just compare it to
kWebGLDebugRendererInfoFieldTrialEnabledName.

(If there's no trial, an empty string is returned.)

[Zhenyao Mo, 2013/10/30 20:20:50]

Done.

See chrome_render_message_filter.cc

+}
+
 }  // namespace anonymous
 
 void GpuDataManagerImplPrivate::InitializeForTesting(
     const std::string& gpu_blacklist_json,
     const gpu::GPUInfo& gpu_info) {
   // This function is for testing only, so disable histograms.
   update_histograms_ = false;
 
   // Prevent all further initialization.
   finalized_ = true;
@@ skipping 927 matching lines @@
 
 void GpuDataManagerImplPrivate::Notify3DAPIBlocked(const GURL& url,
                                                    int render_process_id,
                                                    int render_view_id,
                                                    ThreeDAPIType requester) {
   GpuDataManagerImpl::UnlockedSession session(owner_);
   observer_list_->Notify(&GpuDataManagerObserver::DidBlock3DAPIs,
                          url, render_process_id, render_view_id, requester);
 }
 
+bool GpuDataManagerImplPrivate::IsWebGLDebugRendererInfoAllowed(
+    const GURL& url) const {
+  const CommandLine* command_line = CommandLine::ForCurrentProcess();
+  // Allow someone to disable this extension in WebGL.
+  if (command_line->HasSwitch(switches::kDisableWebGLDebugRendererInfo))
+    return false;
+  // Allow someone to force-enable this extension. This is mostly for
+  // testing purpose.
+  if (command_line->HasSwitch(switches::kEnableWebGLDebugRendererInfo))
+    return true;

[Ken Russell (switch to Gerrit), 2013/10/29 23:15:35]

The test of the kEnableWebGLDebugRendererInfo switch should be moved after the
AllowWebGLDebugRendererInfoForDomain call below so that
ChromeContentBrowserClient::AllowWebGLDebugRendererInfoForDomain can be tested
too (using the kGoogleBaseURL flag).

[Zhenyao Mo, 2013/10/29 23:33:43]

I just realized we can probably get rid of the kEnableWebGLDebugRendererInfo
switch, because we can use --force-fieldtrials combined with --google-base-url
to get this function to return true/false in all possible scenarios.  So
kEnableWebGLdebugRendererInfo doesn't need to be used in tests to emulate any
scenarios.

Also, it seems like finch has a mechanism to automatically insert a flag in
about:flags to let users opt in/out, so probably we don't need the
kDisableWebGLDebugRendererInfo switch also.

What do you think?

[Zhenyao Mo, 2013/10/29 23:43:37]

Never mind about this auto flag thing.  I read the documents more carefully, and
it's not what I thought it was.  We still need the disable- flag here.

[Ken Russell (switch to Gerrit), 2013/10/29 23:58:16]

OK. Using --force-fieldtrials and removing the kEnableWebGLDebugRendererInfo
switch sounds like a good plan.

+
+  if (!GetContentClient()->browser()->AllowWebGLDebugRendererInfoForDomain(url))
+    return false;
+  return IsWebGLDebugRendererInfoFieldTrialEnabled();
+}
+
 void GpuDataManagerImplPrivate::OnGpuProcessInitFailure() {
   gpu_process_accessible_ = false;
   gpu_info_.finalized = true;
   complete_gpu_info_already_requested_ = true;
   // Some observers might be waiting.
   NotifyGpuInfoUpdate();
 }
 
 }  // namespace content