Enable Channel ID

Too many places throughout the codebase assumed that an URLRequestContext
would have a (non-null) ChannelIDService. When the base::Feature kChannelID
is disabled, this results in a null ChannelIDService on the URLRequestContext,
and results in crashes due to null derefs.

Bug: 841730, 841685
Change-Id: Iece0f584d7c05e90ea16da2ea9319b66768ded33
Reviewed-on: https://chromium-review.googlesource.com/1054177Reviewed-by: Ryan Hamilton <rch@chromium.org>
Commit-Queue: Nick Harper <nharper@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557635}

components/network_session_configurator/common/network_features.cc

@@ -4,19 +4,12 @@
 
 #include "components/network_session_configurator/common/network_features.h"
 
-#include "build/build_config.h"
-
 namespace features {
 
 const base::Feature kTokenBinding{"token-binding",
                                   base::FEATURE_DISABLED_BY_DEFAULT};
 
-#if defined(OS_ANDROID)
-// TODO(nharper): Disable kChannelID on all platforms in M69.
 const base::Feature kChannelID{"channel-id", base::FEATURE_ENABLED_BY_DEFAULT};
-#else
-const base::Feature kChannelID{"channel-id", base::FEATURE_DISABLED_BY_DEFAULT};
-#endif  // defined(OS_ANDROID)
 
 const base::Feature kDnsOverHttps{"dns-over-https",
                                   base::FEATURE_DISABLED_BY_DEFAULT};