Adds a chrome://flags support for enabling sub frame translation

Adds #enable-translate-sub-frames flag for Feature "TranslateSubFrames"

Bug: 797328
Change-Id: Ib210a1d5566b43a0dbe75b22ef4e0cd101a404d7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2186366Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Doug Arnett <dougarnett@chromium.org>
Cr-Commit-Position: refs/heads/master@{#766517}

chrome/browser/about_flags.cc

@@ -127,6 +127,7 @@
 #include "components/tracing/common/tracing_switches.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "components/translate/core/browser/translate_ranker_impl.h"
+#include "components/translate/core/common/translate_util.h"
 #include "components/ui_devtools/switches.h"
 #include "components/version_info/version_info.h"
 #include "components/viz/common/features.h"
@@ -5491,6 +5492,11 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(kDiceWebSigninInterceptionFeature)},
 #endif  // ENABLE_DICE_SUPPORT
 
+    {"enable-translate-sub-frames",
+     flag_descriptions::kEnableTranslateSubFramesName,
+     flag_descriptions::kEnableTranslateSubFramesDescription, kOsAll,
+     FEATURE_VALUE_TYPE(translate::kTranslateSubFrames)},
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the

chrome/browser/flag-metadata.json

@@ -2147,6 +2147,11 @@
     // dev and QA.
     "expiry_milestone": -1
   },
+  {
+    "name": "enable-translate-sub-frames",
+    "owners": [ "dougarnett", "chrome-language@google.com" ],
+    "expiry_milestone": 86
+  },
   {
     "name": "enable-ui-devtools",
     "owners": [ "//components/ui_devtools/OWNERS" ],

chrome/browser/flag_descriptions.cc

@@ -745,6 +745,10 @@ const char kEnablePortalsCrossOriginDescription[] =
     "Allows portals to load cross-origin URLs in addition to same-origin ones."
     " Has no effect if Portals are not enabled.";
 
+const char kEnableTranslateSubFramesName[] = "Translate sub frames";
+const char kEnableTranslateSubFramesDescription[] =
+    "Enable the translation of sub frames (as well as the main frame)";
+
 const char kCorsForContentScriptsName[] = "CORS for content scripts";
 const char kCorsForContentScriptsDescription[] =
     "Prevent content scripts of Chrome Extensions from bypassing CORS.";

chrome/browser/flag_descriptions.h

@@ -425,6 +425,9 @@ extern const char kEnableNetworkLoggingToFileDescription[];
 extern const char kEnableNetworkServiceInProcessName[];
 extern const char kEnableNetworkServiceInProcessDescription[];
 
+extern const char kEnableTranslateSubFramesName[];
+extern const char kEnableTranslateSubFramesDescription[];
+
 extern const char kCorsForContentScriptsName[];
 extern const char kCorsForContentScriptsDescription[];
 

tools/metrics/histograms/enums.xml

@@ -39284,6 +39284,7 @@ from previous Chrome versions.
   <int value="-680787130" label="ExperimentalVRFeatures:disabled"/>
   <int value="-680589442" label="MacRTL:disabled"/>
   <int value="-679500267" label="UseXpsForPrinting:disabled"/>
+  <int value="-678184617" label="TranslateSubFrames:disabled"/>
   <int value="-674804217" label="SoleIntegration:enabled"/>
   <int value="-673804828" label="EnablePlayStoreAppSearch:disabled"/>
   <int value="-673149604" label="RelatedSearches:enabled"/>
@@ -41482,6 +41483,7 @@ from previous Chrome versions.
   <int value="1914347357" label="AutofillEnableVirtualCard:disabled"/>
   <int value="1915028326" label="BuiltInModuleKvStorage:disabled"/>
   <int value="1915178511" label="disable-blink-features"/>
+  <int value="1916637435" label="TranslateSubFrames:enabled"/>
   <int value="1918984253"
       label="OmniboxUIExperimentBlueSearchLoopAndSearchQuery:disabled"/>
   <int value="1919917329" label="ImplicitRootScroller:disabled"/>