Add feature to enable SODA for dogfood

This CL adds a feature that will be used to dogfood the Speech On-Device
API (SODA), which will power the Chrome Live Caption feature.

Bug: 1128723
Change-Id: I99724f7ada8117eb6b664e888bd840572169cdb6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2411341
Commit-Queue: Evan Liu <evliu@google.com>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807626}

media/base/media_switches.cc

@@ -456,10 +456,15 @@ const base::Feature kVideoBlitColorAccuracy{"video-blit-color-accuracy",
 const base::Feature kExternalClearKeyForTesting{
     "ExternalClearKeyForTesting", base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Enables the LiveCaption feature.
+// Enables the Live Caption feature.
 const base::Feature kLiveCaption{"LiveCaption",
                                  base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Use the Speech On-Device API (SODA) to power the Live Caption feature instead
+// of the Cloud-based Open Speech API.
+const base::Feature kUseSodaForLiveCaption{"UseSodaForLiveCaption",
+                                           base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Prevents UrlProvisionFetcher from making a provisioning request. If
 // specified, any provisioning request made will not be sent to the provisioning
 // server, and the response will indicate a failure to communicate with the

media/base/media_switches.h

@@ -177,6 +177,7 @@ MEDIA_EXPORT extern const base::Feature kUseFakeDeviceForMediaStream;
 MEDIA_EXPORT extern const base::Feature kUseMediaHistoryStore;
 MEDIA_EXPORT extern const base::Feature kUseNewMediaCache;
 MEDIA_EXPORT extern const base::Feature kUseR16Texture;
+MEDIA_EXPORT extern const base::Feature kUseSodaForLiveCaption;
 MEDIA_EXPORT extern const base::Feature kVaapiLowPowerEncoderGen9x;
 MEDIA_EXPORT extern const base::Feature kVaapiVP8Encoder;
 MEDIA_EXPORT extern const base::Feature kVaapiVP9Encoder;