Wire up chrome field trials with webrtc.

BUG=367114

Review URL: https://codereview.chromium.org/272503004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270994 0039d316-1c4b-4281-b951-d872f2087c98

third_party/libjingle/overrides/init_webrtc.cc

@@ -8,6 +8,7 @@
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
+#include "base/metrics/field_trial.h"
 #include "base/native_library.h"
 #include "base/path_service.h"
 #include "talk/base/basictypes.h"
@@ -42,6 +43,17 @@ bool InitializeWebRtcModule() {
   return true;
 }
 
+// Define webrtc:field_trial::FindFullName to provide webrtc with a field trial
+// implementation. When compiled as a static library this can be done directly
+// and without pointers to functions.
+namespace webrtc {
+namespace field_trial {
+std::string FindFullName(const std::string& trial_name) {
+  return base::FieldTrialList::FindFullName(trial_name);
+}
+}  // namespace field_trial
+}  // namespace webrtc
+
 #else  // !LIBPEERCONNECTION_LIB
 
 // When being compiled as a shared library, we need to bridge the gap between
@@ -117,6 +129,7 @@ bool InitializeWebRtcModule() {
 #if !defined(OS_MACOSX) && !defined(OS_ANDROID)
       &Allocate, &Dellocate,
 #endif
+      &base::FieldTrialList::FindFullName,
       logging::GetLogMessageHandler(),
       &GetCategoryGroupEnabled, &AddTraceEvent,
       &g_create_webrtc_media_engine, &g_destroy_webrtc_media_engine,

third_party/libjingle/overrides/init_webrtc.h

@@ -23,6 +23,8 @@ namespace webrtc {
 class AudioDeviceModule;
 }  // namespace webrtc
 
+typedef std::string (*FieldTrialFindFullName)(const std::string& trial_name);
+
 typedef cricket::MediaEngineInterface* (*CreateWebRtcMediaEngineFunction)(
     webrtc::AudioDeviceModule* adm,
     webrtc::AudioDeviceModule* adm_sc,
@@ -46,6 +48,7 @@ typedef bool (*InitializeModuleFunction)(
     AllocateFunction alloc,
     DellocateFunction dealloc,
 #endif
+    FieldTrialFindFullName field_trial_find,
     logging::LogMessageHandlerFunction log_handler,
     webrtc::GetCategoryEnabledPtr trace_get_category_enabled,
     webrtc::AddTraceEventPtr trace_add_trace_event,

third_party/libjingle/overrides/initialize_module.cc

@@ -38,6 +38,21 @@ cricket::MediaEngineInterface* CreateWebRtcMediaEngine(
 
 void DestroyWebRtcMediaEngine(cricket::MediaEngineInterface* media_engine);
 
+// Define webrtc:field_trial::FindFullName to provide webrtc with a field trial
+// implementation. The implementation is provided by the loader via the
+// InitializeModule.
+namespace {
+FieldTrialFindFullName g_field_trial_find_ = NULL;
+}
+
+namespace webrtc {
+namespace field_trial {
+std::string FindFullName(const std::string& trial_name) {
+  return g_field_trial_find_(trial_name);
+}
+}  // namespace field_trial
+}  // namespace webrtc
+
 extern "C" {
 
 // Initialize logging, set the forward allocator functions (not on mac), and
@@ -49,6 +64,7 @@ bool InitializeModule(const CommandLine& command_line,
                       AllocateFunction alloc,
                       DellocateFunction dealloc,
 #endif
+                      FieldTrialFindFullName field_trial_find,
                       logging::LogMessageHandlerFunction log_handler,
                       webrtc::GetCategoryEnabledPtr trace_get_category_enabled,
                       webrtc::AddTraceEventPtr trace_add_trace_event,
@@ -61,6 +77,8 @@ bool InitializeModule(const CommandLine& command_line,
   g_dealloc = dealloc;
 #endif
 
+  g_field_trial_find_ = field_trial_find;
+
   *create_media_engine = &CreateWebRtcMediaEngine;
   *destroy_media_engine = &DestroyWebRtcMediaEngine;
   *init_diagnostic_logging = &talk_base::InitDiagnosticLoggingDelegateFunction;