Disable "Ok Google" hotwording in open source builds by default.

The compile-time flag "enable_hotwording" is now tied to
branding=Chrome (false by default unless making a Google Chrome build).

Note: Chromium will no longer download/install the Hotword Shared
Module, and will automatically remove the Hotword Shared Module on
startup if it was previously installed. To keep this functionality, add
"enable_hotwording=1" to GYP_DEFINES.

BUG=500922

Review URL: https://codereview.chromium.org/1200413003

Cr-Commit-Position: refs/heads/master@{#335874}
(cherry picked from commit 0366a5184a70b3eefb5fcef2c2e13721669f00d8)

Fix up HotwordServiceTest on Chrome-branded builds.

The ENABLE_HOTWORDING flag is not available in
hotword_service_unittest.cc, so all tests were assuming hotwording was
disabled (since r333548). This has been failing on Official builders
since r335874.

Since it's hard to resolve this in a simple way (we want to merge these
changes), just disabling the tests is the cleanest option for now.

BUG=503963

Review URL: https://codereview.chromium.org/1207163002

Cr-Commit-Position: refs/heads/master@{#336091}
(cherry picked from commit 8ef0bc35b1594ad013dc2ae1d6893e0091919271)

Resolved merge conflict: Disabled IsHotwordAllowedDisabledFieldTrial and
IsHotwordAllowedInvalidFieldTrial. These tests were deleted before the
upstream patch landed.

(Merge approval on http://crbug.com/500922#c69)

R=thakis@chromium.org
TBR=thakis@chromium.org

Committed: https://chromium.googlesource.com/chromium/src/+/86fb78f02492b2990307ed427c09670f2fff0d3b

Review URL: https://codereview.chromium.org/1211273003.

Cr-Commit-Position: refs/branch-heads/2403@{#418}
Cr-Branched-From: f54b8097a9c45ed4ad308133d49f05325d6c5070-refs/heads/master@{#330231}
3 files changed