Add build flag to disable hotwording.

Hotwording downloads a shared module from the web store containing a NaCl module. There is a desire to build and distribute Chromium without this happening. This change adds an "enable_hotwording" build flag that is enabled by default, but can be disabled at compile time.

BUG=491435

Review URL: https://codereview.chromium.org/1160243004

Cr-Commit-Position: refs/heads/master@{#333548}
(cherry picked from commit f269d3b548203e217e8c0080c2e22e7ae3efb51e)

Resolved merge conflict: Remove the body of
IsHotwordAllowedDisabledFieldTrial and IsHotwordAllowedInvalidFieldTrial
when ENABLE_HOTWORDING is false. These tests were deleted before the
upstream patch landed.

(Merge approval on http://crbug.com/500922#c69)
TBR=thestig@chromium.org,scottmg@chromium.org

Review URL: https://codereview.chromium.org/1218693004.

Cr-Commit-Position: refs/branch-heads/2403@{#412}
Cr-Branched-From: f54b8097a9c45ed4ad308133d49f05325d6c5070-refs/heads/master@{#330231}

5 files changed, 28 insertions, 0 deletions

diff --git a/build/common.gypi b/build/common.gypi
index 339cc75..ddb075c 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -381,6 +381,9 @@
       # Web speech is enabled by default. Set to 0 to disable.
       'enable_web_speech%': 1,
 
+      # 'Ok Google' hotwording is enabled by default. Set to 0 to disable.
+      'enable_hotwording%': 1,
+
       # Notifications are compiled in by default. Set to 0 to disable.
       'notifications%' : 1,
 
@@ -1134,6 +1137,7 @@
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'enable_web_speech%': '<(enable_web_speech)',
+    'enable_hotwording%': '<(enable_hotwording)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 5152d83..6ccb079 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -18,6 +18,11 @@ if (is_desktop_linux) {
   import("//build/config/linux/pkg_config.gni")
 }
 
+declare_args() {
+  # 'Ok Google' hotwording is enabled.
+  enable_hotwording = true
+}
+
 about_credits_file = "$target_gen_dir/about_credits.html"
 additional_modules_list_file =
     "$root_gen_dir/chrome/browser/internal/additional_modules_list.txt"
@@ -455,6 +460,10 @@ source_set("browser") {
     }
   }
 
+  if (enable_hotwording) {
+    defines += [ "ENABLE_HOTWORDING" ]
+  }
+
   if (is_linux) {
     deps += [
       "//device/media_transfer_protocol",
diff --git a/chrome/browser/search/hotword_service.cc b/chrome/browser/search/hotword_service.cc
index 0cf3c60..e93789b 100644
--- a/chrome/browser/search/hotword_service.cc
+++ b/chrome/browser/search/hotword_service.cc
@@ -642,6 +642,7 @@ bool HotwordService::IsServiceAvailable() {
 }
 
 bool HotwordService::IsHotwordAllowed() {
+#if defined(ENABLE_HOTWORDING)
   std::string group = base::FieldTrialList::FindFullName(
       hotword_internal::kHotwordFieldTrialName);
   // Allow hotwording by default, and only disable if the field trial has been
@@ -650,6 +651,9 @@ bool HotwordService::IsHotwordAllowed() {
     return false;
 
   return DoesHotwordSupportLanguage(profile_);
+#else
+  return false;
+#endif
 }
 
 bool HotwordService::IsOptedIntoAudioLogging() {
diff --git a/chrome/browser/search/hotword_service_unittest.cc b/chrome/browser/search/hotword_service_unittest.cc
index a3aef47..e78e2e7 100644
--- a/chrome/browser/search/hotword_service_unittest.cc
+++ b/chrome/browser/search/hotword_service_unittest.cc
@@ -158,6 +158,7 @@ INSTANTIATE_TEST_CASE_P(HotwordServiceTests,
                             extension_misc::kHotwordSharedModuleId));
 
 TEST_P(HotwordServiceTest, IsHotwordAllowedDisabledFieldTrial) {
+#if defined(ENABLE_HOTWORDING)
   TestingProfile::Builder profile_builder;
   scoped_ptr<TestingProfile> profile = profile_builder.Build();
 
@@ -190,9 +191,11 @@ TEST_P(HotwordServiceTest, IsHotwordAllowedDisabledFieldTrial) {
   // Test that incognito returns false as well.
   EXPECT_FALSE(HotwordServiceFactory::IsHotwordAllowed(
       profile->GetOffTheRecordProfile()));
+#endif
 }
 
 TEST_P(HotwordServiceTest, IsHotwordAllowedInvalidFieldTrial) {
+#if defined(ENABLE_HOTWORDING)
   TestingProfile::Builder profile_builder;
   scoped_ptr<TestingProfile> profile = profile_builder.Build();
 
@@ -213,9 +216,11 @@ TEST_P(HotwordServiceTest, IsHotwordAllowedInvalidFieldTrial) {
   // Test that incognito returns false as well.
   EXPECT_FALSE(HotwordServiceFactory::IsHotwordAllowed(
       profile->GetOffTheRecordProfile()));
+#endif
 }
 
 TEST_P(HotwordServiceTest, IsHotwordAllowedLocale) {
+#if defined(ENABLE_HOTWORDING)
   TestingProfile::Builder profile_builder;
   scoped_ptr<TestingProfile> profile = profile_builder.Build();
 
@@ -246,6 +251,7 @@ TEST_P(HotwordServiceTest, IsHotwordAllowedLocale) {
   Profile* otr_profile = profile->GetOffTheRecordProfile();
   SetApplicationLocale(otr_profile, "en");
   EXPECT_FALSE(HotwordServiceFactory::IsHotwordAllowed(otr_profile));
+#endif  // defined(ENABLE_HOTWORDING)
 }
 
 TEST_P(HotwordServiceTest, ShouldReinstallExtension) {
@@ -302,6 +308,7 @@ TEST_P(HotwordServiceTest, PreviousLanguageSetOnInstall) {
 }
 
 TEST_P(HotwordServiceTest, UninstallReinstallTriggeredCorrectly) {
+#if defined(ENABLE_HOTWORDING)
   InitializeEmptyExtensionService();
   service_->Init();
 
@@ -372,6 +379,7 @@ TEST_P(HotwordServiceTest, UninstallReinstallTriggeredCorrectly) {
   EXPECT_TRUE(HotwordServiceFactory::IsHotwordAllowed(profile()));
   EXPECT_FALSE(hotword_service->MaybeReinstallHotwordExtension());
   EXPECT_EQ(1, hotword_service->uninstall_count());  // no change
+#endif  // defined(ENABLE_HOTWORDING)
 }
 
 TEST_P(HotwordServiceTest, DisableAlwaysOnOnLanguageChange) {
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 6d323eb..1aaedba 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -3529,6 +3529,9 @@
         ['enable_session_service==1', {
           'sources': [ '<@(chrome_browser_session_service_sources)' ],
         }],
+        ['enable_hotwording==1', {
+          'defines': [ 'ENABLE_HOTWORDING' ],
+        }],
         ['OS!="android" and OS!="ios" and chromeos==0', {
           'sources': [ '<@(chrome_browser_desktop_sources)' ],
         }],