Android: enable/disable WebRTC HW H264 with a flag.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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 "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 648 matching lines @@
      switches::kMaterialSecurityVerboseShowAllNonAnimated},
     {IDS_FLAGS_MATERIAL_SECURITY_VERBOSE_SHOW_NONSECURE_ANIMATED,
      switches::kMaterialSecurityVerbose,
      switches::kMaterialSecurityVerboseShowNonSecureAnimated},
     {IDS_FLAGS_MATERIAL_SECURITY_VERBOSE_SHOW_NONSECURE_NONANIMATED,
      switches::kMaterialSecurityVerbose,
      switches::kMaterialSecurityVerboseShowNonSecureNonAnimated},
 };
 #endif  // defined(OS_MACOSX)
 
+#if defined(ENABLE_WEBRTC)
+const FeatureEntry::Choice kDisableWebRtcHWEncodingChoices[] = {
+    {IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
+    {IDS_FLAGS_WEBRTC_HW_ENCODING_ALL, switches::kDisableWebRtcHWEncoding, ""},
+    {IDS_FLAGS_WEBRTC_HW_ENCODING_VPX, switches::kDisableWebRtcHWEncoding,
+     switches::kDisableWebRtcHWEncodingVPx},
+    {IDS_FLAGS_WEBRTC_HW_ENCODING_H264, switches::kDisableWebRtcHWEncoding,
+     switches::kDisableWebRtcHWEncodingH264},
+    {IDS_FLAGS_WEBRTC_HW_ENCODING_NONE, switches::kDisableWebRtcHWEncoding,
+     switches::kDisableWebRtcHWEncodingNone},

[watk, 2016/10/01 01:06:53]

The double negative is confusing. Can it be called kEnableWebRtcHWEncoding?

[braveyao, 2016/10/03 23:50:14]

Yes it's a bit confusing. But it works as a pair to
'switches::kDisableWebRtcHWDecoding'. If I recall it correctly, they are both
evolved from 'kEnableWebRtcHWEncoding/Decoding' quite a while ago.
CrOS needs it to be 'kDisableWebRtcHWEncoding' as HW codec is the first choice
on it. Android may need it soon. So I suppose this should be OK. WDYT?

+};
+#endif
+
 // RECORDING USER METRICS FOR FLAGS:
 // -----------------------------------------------------------------------------
 // The first line of the entry is the internal name.
 //
 // To add a new entry, add to the end of kFeatureEntries. There are two
 // distinct types of entries:
 // . SINGLE_VALUE: entry is either on or off. Use the SINGLE_VALUE_TYPE
 //   macro for this type supplying the command line to the macro.
 // . MULTI_VALUE: a list of choices, the first of which should correspond to a
 //   deactivated state for this lab (i.e. no command line option).  To specify
@@ skipping 36 matching lines @@
     {"gl-composited-texture-quad-borders",
      IDS_FLAGS_GL_COMPOSITED_TEXTURE_QUAD_BORDERS,
      IDS_FLAGS_GL_COMPOSITED_TEXTURE_QUAD_BORDERS_DESCRIPTION, kOsAll,
      SINGLE_VALUE_TYPE(cc::switches::kGlCompositedTextureQuadBorder)},
 #if defined(ENABLE_WEBRTC)
     {"disable-webrtc-hw-decoding", IDS_FLAGS_WEBRTC_HW_DECODING_NAME,
      IDS_FLAGS_WEBRTC_HW_DECODING_DESCRIPTION, kOsAndroid | kOsCrOS,
      SINGLE_DISABLE_VALUE_TYPE(switches::kDisableWebRtcHWDecoding)},
     {"disable-webrtc-hw-encoding", IDS_FLAGS_WEBRTC_HW_ENCODING_NAME,
      IDS_FLAGS_WEBRTC_HW_ENCODING_DESCRIPTION, kOsAndroid | kOsCrOS,
-     SINGLE_DISABLE_VALUE_TYPE(switches::kDisableWebRtcHWEncoding)},
+     MULTI_VALUE_TYPE(kDisableWebRtcHWEncodingChoices)},
     {"enable-webrtc-stun-origin", IDS_FLAGS_WEBRTC_STUN_ORIGIN_NAME,
      IDS_FLAGS_WEBRTC_STUN_ORIGIN_DESCRIPTION, kOsAll,
      SINGLE_VALUE_TYPE(switches::kEnableWebRtcStunOrigin)},
 #endif
 #if defined(OS_ANDROID)
     {"enable-osk-overscroll", IDS_FLAGS_ENABLE_OSK_OVERSCROLL_NAME,
      IDS_FLAGS_ENABLE_OSK_OVERSCROLL_DESCRIPTION, kOsAndroid,
      SINGLE_VALUE_TYPE(switches::kEnableOSKOverscroll)},
 #endif
   // Native client is compiled out when DISABLE_NACL is defined.
@@ skipping 1571 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags