Expose a postMessage API to dynamic modules

This uses a PostMessageHandler internally to communicate with the web contents.
The PostMessageHandler is initialised once the dynamic module has been loaded
and is reset each time the web contents change.

A new class, ActivityDelegatePostMessageBackend, replaces the service backend
usually used by PostMessageHandler and forwards all events along to the
dynamic module if it's present.

Bug: 898840
Change-Id: Ia308c84cd771d2fdb96fc076472488fc48946162
Reviewed-on: https://chromium-review.googlesource.com/c/1323669
Commit-Queue: David Barker <barkerd@google.com>
Reviewed-by: Michael van Ouwerkerk <mvanouwerkerk@chromium.org>
Reviewed-by: Peter Conn <peconn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607587}

chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java

@@ -163,6 +163,7 @@ public abstract class ChromeFeatureList {
     public static final String CCT_BACKGROUND_TAB = "CCTBackgroundTab";
     public static final String CCT_MODULE = "CCTModule";
     public static final String CCT_MODULE_CACHE = "CCTModuleCache";
+    public static final String CCT_MODULE_POST_MESSAGE = "CCTModulePostMessage";
     public static final String CCT_EXTERNAL_LINK_HANDLING = "CCTExternalLinkHandling";
     public static final String CCT_PARALLEL_REQUEST = "CCTParallelRequest";
     public static final String CCT_POST_MESSAGE_API = "CCTPostMessageAPI";

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java

@@ -24,7 +24,9 @@ import android.support.annotation.CallSuper;
 import android.support.annotation.IntDef;
 import android.support.annotation.Nullable;
 import android.support.customtabs.CustomTabsIntent;
+import android.support.customtabs.CustomTabsService;
 import android.support.customtabs.CustomTabsSessionToken;
+import android.support.customtabs.PostMessageBackend;
 import android.support.v4.app.ActivityOptionsCompat;
 import android.text.TextUtils;
 import android.util.Pair;
@@ -64,6 +66,7 @@ import org.chromium.chrome.browser.appmenu.AppMenuPropertiesDelegate;
 import org.chromium.chrome.browser.autofill_assistant.AutofillAssistantUiController;
 import org.chromium.chrome.browser.browserservices.BrowserSessionContentHandler;
 import org.chromium.chrome.browser.browserservices.BrowserSessionContentUtils;
+import org.chromium.chrome.browser.browserservices.PostMessageHandler;
 import org.chromium.chrome.browser.compositor.layouts.LayoutManager;
 import org.chromium.chrome.browser.contextual_suggestions.ContextualSuggestionsModule;
 import org.chromium.chrome.browser.customtabs.dependency_injection.CustomTabActivityComponent;
@@ -192,6 +195,8 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
     private ModuleEntryPoint mModuleEntryPoint;
     @Nullable
     private ActivityDelegate mModuleActivityDelegate;
+    @Nullable
+    private PostMessageHandler mDynamicModulePostMessageHandler;
 
     private boolean mModuleOnStartPending;
     private boolean mModuleOnResumePending;
@@ -359,9 +364,22 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
             mConnection.setActivityDelegateForSession(mSession, mModuleActivityDelegate,
                     mModuleEntryPoint.getModuleVersion());
             mModuleCallback = null;
+
+            // Initialise the PostMessageHandler for the current web contents.
+            maybeInitialiseDynamicModulePostMessageHandler(
+                    new ActivityDelegatePostMessageBackend());
         }
     }
 
+    @VisibleForTesting
+    void maybeInitialiseDynamicModulePostMessageHandler(PostMessageBackend backend) {
+        // Only initialise the handler if the feature is enabled.
+        if (!ChromeFeatureList.isEnabled(ChromeFeatureList.CCT_MODULE_POST_MESSAGE)) return;
+
+        mDynamicModulePostMessageHandler = new PostMessageHandler(backend);
+        mDynamicModulePostMessageHandler.reset(getCurrentWebContents());
+    }
+
     private void startModule() {
         assert mModuleActivityDelegate != null;
 
@@ -410,6 +428,42 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
                 isModuleManagedUrl(mIntentDataProvider.getUrlToLoad()));
     }
 
+    /**
+     * Requests a postMessage channel for a loaded dynamic module.
+     *
+     * <p>The initialisation work is posted to the UI thread because this method will be called by
+     * the dynamic module so we can't be sure of the thread it will be called on.
+     *
+     * @param postMessageOrigin The origin to use for messages posted to this channel.
+     * @return Whether it was possible to request a channel. Will return false if the dynamic module
+     *         has not been loaded.
+     */
+    public boolean requestPostMessageChannel(Uri postMessageOrigin) {
+        if (mDynamicModulePostMessageHandler == null) return false;
+
+        ThreadUtils.postOnUiThread(
+            () -> mDynamicModulePostMessageHandler.initializeWithPostMessageUri(postMessageOrigin));
+        return true;
+    }
+
+    /**
+     * Posts a message from a loaded dynamic module.
+     *
+     * @param message The message to post to the page. Nothing is assumed about the format of the
+     *                message; we just post it as-is.
+     * @return Whether it was possible to post the message. Will always return {@link
+     *         CustomTabsService#RESULT_FAILURE_DISALLOWED} if the dynamic module has not been
+     *         loaded.
+     */
+    public int postMessage(String message) {
+        // Use of the postMessage API is disallowed when the module has not been loaded.
+        if (mDynamicModulePostMessageHandler == null) {
+            return CustomTabsService.RESULT_FAILURE_DISALLOWED;
+        }
+
+        return mDynamicModulePostMessageHandler.postMessageFromClientApp(message);
+    }
+
     @Override
     public boolean shouldAllocateChildConnection() {
         return !mHasCreatedTabEarly && !mHasSpeculated
@@ -730,7 +784,7 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
         RecordHistogram.recordEnumeratedHistogram("CustomTabs.WebContentsStateOnLaunch",
                 webContentsStateOnLaunch, WebContentsState.NUM_ENTRIES);
 
-        mConnection.resetPostMessageHandlerForSession(mSession, webContents);
+        resetPostMessageHandlersForCurrentSession(webContents);
 
         return webContents;
     }
@@ -743,6 +797,14 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
         return asyncParams.getWebContents();
     }
 
+    private void resetPostMessageHandlersForCurrentSession(WebContents newWebContents) {
+        mConnection.resetPostMessageHandlerForSession(mSession, newWebContents);
+
+        if (mDynamicModulePostMessageHandler != null) {
+            mDynamicModulePostMessageHandler.reset(newWebContents);
+        }
+    }
+
     /**
      * Initializes tab handlers and observers, e.g., for metrics.
      *
@@ -1371,7 +1433,7 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
             mMainTab = null;
             // mHasCreatedTabEarly == true => mMainTab != null in the rest of the code.
             mHasCreatedTabEarly = false;
-            mConnection.resetPostMessageHandlerForSession(mSession, null);
+            resetPostMessageHandlersForCurrentSession(null);
             tab.detachAndStartReparenting(intent, startActivityOptions, finalizeCallback);
         } else {
             // Temporarily allowing disk access while fixing. TODO: http://crbug.com/581860
@@ -1505,6 +1567,38 @@ public class CustomTabActivity extends ChromeActivity<CustomTabActivityComponent
         }
     }
 
+    /**
+     * A {@link PostMessageBackend} which delegates incoming notifications to the {@link
+     * ActivityDelegate} from the dynamic module.
+     *
+     * <p>If the dynamic module is not loaded, we ignore incoming notifications and always return
+     * false.
+     */
+    private class ActivityDelegatePostMessageBackend implements PostMessageBackend {
+        @Override
+        public boolean onPostMessage(String message, Bundle extras) {
+            if (mModuleActivityDelegate != null) {
+                mModuleActivityDelegate.onPostMessage(message);
+                return true;
+            }
+            return false;
+        }
+
+        @Override
+        public boolean onNotifyMessageChannelReady(Bundle extras) {
+            if (mModuleActivityDelegate != null) {
+                mModuleActivityDelegate.onMessageChannelReady();
+                return true;
+            }
+            return false;
+        }
+
+        @Override
+        public void onDisconnectChannel(Context appContext) {
+            // Nothing to do.
+        }
+    }
+
     @Override
     protected CustomTabActivityComponent createComponent(ChromeActivityCommonsModule commonsModule,
             ContextualSuggestionsModule contextualSuggestionsModule) {

chrome/android/java/src/org/chromium/chrome/browser/customtabs/dynamicmodule/ActivityDelegate.java

@@ -15,112 +15,89 @@ import android.os.RemoteException;
 public class ActivityDelegate {
     private final IActivityDelegate mActivityDelegate;
 
-    public ActivityDelegate(IActivityDelegate activityDelegate) {
-        mActivityDelegate = activityDelegate;
-    }
+    private interface RemoteRunnable { void run() throws RemoteException; }
 
-    public void onCreate(Bundle savedInstanceState) {
+    private interface RemoteCallable<T> { T call() throws RemoteException; }
+
+    private void safeRun(RemoteRunnable runnable) {
         try {
-            mActivityDelegate.onCreate(savedInstanceState);
+            runnable.run();
         } catch (RemoteException e) {
             assert false;
         }
     }
 
-    public void onPostCreate(Bundle savedInstanceState) {
+    private <T> T safeCall(RemoteCallable<T> callable, T defaultReturn) {
         try {
-            mActivityDelegate.onPostCreate(savedInstanceState);
+            return callable.call();
         } catch (RemoteException e) {
             assert false;
         }
+
+        return defaultReturn;
+    }
+
+    public ActivityDelegate(IActivityDelegate activityDelegate) {
+        mActivityDelegate = activityDelegate;
+    }
+
+    public void onCreate(Bundle savedInstanceState) {
+        safeRun(() -> mActivityDelegate.onCreate(savedInstanceState));
+    }
+
+    public void onPostCreate(Bundle savedInstanceState) {
+        safeRun(() -> mActivityDelegate.onPostCreate(savedInstanceState));
     }
 
     public void onStart() {
-        try {
-            mActivityDelegate.onStart();
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(mActivityDelegate::onStart);
     }
 
     public void onStop() {
-        try {
-            mActivityDelegate.onStop();
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(mActivityDelegate::onStop);
     }
 
     public void onWindowFocusChanged(boolean hasFocus) {
-        try {
-            mActivityDelegate.onWindowFocusChanged(hasFocus);
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(() -> mActivityDelegate.onWindowFocusChanged(hasFocus));
     }
 
     public void onSaveInstanceState(Bundle outState) {
-        try {
-            mActivityDelegate.onSaveInstanceState(outState);
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(() -> mActivityDelegate.onSaveInstanceState(outState));
     }
 
     public void onRestoreInstanceState(Bundle savedInstanceState) {
-        try {
-            mActivityDelegate.onRestoreInstanceState(savedInstanceState);
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(() -> mActivityDelegate.onRestoreInstanceState(savedInstanceState));
     }
 
     public void onResume() {
-        try {
-            mActivityDelegate.onResume();
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(mActivityDelegate::onResume);
     }
 
     public void onPause() {
-        try {
-            mActivityDelegate.onPause();
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(mActivityDelegate::onPause);
     }
 
     public void onDestroy() {
-        try {
-            mActivityDelegate.onDestroy();
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(mActivityDelegate::onDestroy);
     }
 
     public boolean onBackPressed() {
-        try {
-            return mActivityDelegate.onBackPressed();
-        } catch (RemoteException e) {
-            assert false;
-        }
-        return false;
+        return safeCall(mActivityDelegate::onBackPressed, false);
     }
 
     public void onBackPressedAsync(Runnable notHandledRunnable) {
-        try {
-            mActivityDelegate.onBackPressedAsync(ObjectWrapper.wrap(notHandledRunnable));
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(() -> mActivityDelegate.onBackPressedAsync(ObjectWrapper.wrap(notHandledRunnable)));
     }
 
     public void onNavigationEvent(int navigationEvent, Bundle extras) {
-        try {
-            mActivityDelegate.onNavigationEvent(navigationEvent, extras);
-        } catch (RemoteException e) {
-            assert false;
-        }
+        safeRun(() -> mActivityDelegate.onNavigationEvent(navigationEvent, extras));
+    }
+
+    public void onMessageChannelReady() {
+        safeRun(mActivityDelegate::onMessageChannelReady);
+    }
+
+    public void onPostMessage(String message) {
+        safeRun(() -> mActivityDelegate.onPostMessage(message));
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/customtabs/dynamicmodule/ActivityHostImpl.java

@@ -48,4 +48,14 @@ public class ActivityHostImpl extends BaseActivityHost {
     public void setTopBarView(IObjectWrapper topBarView) {
         mActivity.setTopBarContentView(ObjectWrapper.unwrap(topBarView, View.class));
     }
+
+    @Override
+    public boolean requestPostMessageChannel(Uri postMessageOrigin) {
+        return mActivity.requestPostMessageChannel(postMessageOrigin);
+    }
+
+    @Override
+    public int postMessage(String message) {
+        return mActivity.postMessage(message);
+    }
 }

chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java

@@ -8,6 +8,7 @@ import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.fail;
 
 import static org.chromium.base.test.util.Restriction.RESTRICTION_TYPE_NON_LOW_END_DEVICE;
 import static org.chromium.chrome.browser.customtabs.CustomTabActivityTestRule.LONG_TIMEOUT_MS;
@@ -37,6 +38,7 @@ import android.support.customtabs.CustomTabsIntent;
 import android.support.customtabs.CustomTabsService;
 import android.support.customtabs.CustomTabsSession;
 import android.support.customtabs.CustomTabsSessionToken;
+import android.support.customtabs.PostMessageBackend;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.MediumTest;
 import android.support.test.filters.SmallTest;
@@ -108,8 +110,10 @@ import org.chromium.chrome.browser.util.ColorUtils;
 import org.chromium.chrome.test.ChromeActivityTestRule;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.util.ChromeTabUtils;
+import org.chromium.chrome.test.util.browser.Features.DisableFeatures;
 import org.chromium.chrome.test.util.browser.Features.EnableFeatures;
 import org.chromium.chrome.test.util.browser.LocationSettingsTestUtil;
+import org.chromium.chrome.test.util.browser.TabTitleObserver;
 import org.chromium.chrome.test.util.browser.contextmenu.ContextMenuUtils;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.browser.WebContentsObserver;
@@ -141,6 +145,7 @@ public class CustomTabActivityTest {
     public CustomTabActivityTestRule mCustomTabActivityTestRule = new CustomTabActivityTestRule();
 
     private static final int TIMEOUT_PAGE_LOAD_SECONDS = 10;
+    public static final int TITLE_UPDATE_TIMEOUT_MS = 3000;
     private static final int MAX_MENU_CUSTOM_ITEMS = 5;
     private static final int NUM_CHROME_MENU_ITEMS = 5;
     private static final String TEST_PAGE = "/chrome/test/data/android/google.html";
@@ -190,6 +195,7 @@ public class CustomTabActivityTest {
             + "        }"
             + "   </script>"
             + "</body></html>";
+    private static final Uri FAKE_ORIGIN_URI = Uri.parse("android-app://com.google.test");
 
     private static int sIdToIncrement = 1;
 
@@ -1627,13 +1633,7 @@ public class CustomTabActivityTest {
         });
         Assert.assertTrue(connection.postMessage(token, "New title", null)
                 == CustomTabsService.RESULT_SUCCESS);
-        CriteriaHelper.pollInstrumentationThread(new Criteria() {
-            @Override
-            public boolean isSatisfied() {
-                final Tab currentTab = mCustomTabActivityTestRule.getActivity().getActivityTab();
-                return "New title".equals(currentTab.getTitle());
-            }
-        });
+        waitForTitle("New title");
     }
 
     /**
@@ -1842,13 +1842,148 @@ public class CustomTabActivityTest {
         titleString += newMessage;
 
         final String title = titleString;
-        CriteriaHelper.pollUiThread(new Criteria() {
+        waitForTitle(title);
+    }
+
+    /**
+     * Tests the sent postMessage requests not only return success, but is also received by page.
+     */
+    @Test
+    @SmallTest
+    @EnableFeatures(ChromeFeatureList.CCT_MODULE_POST_MESSAGE)
+    public void testPostMessageFromDynamicModuleReceivedInPage() throws Exception {
+        final String url =
+                mWebServer.setResponse("/test.html", TITLE_FROM_POSTMESSAGE_TO_CHANNEL, null);
+
+        Context context = InstrumentationRegistry.getTargetContext();
+        Intent intent = CustomTabsTestUtils.createMinimalCustomTabIntent(context, url);
+        mCustomTabActivityTestRule.startCustomTabActivityWithIntent(intent);
+
+        ChromeTabUtils.waitForTabPageLoaded(getActivity().getActivityTab(), url);
+
+        getActivity().maybeInitialiseDynamicModulePostMessageHandler(new PostMessageBackend() {
             @Override
-            public boolean isSatisfied() {
-                final Tab currentTab = mCustomTabActivityTestRule.getActivity().getActivityTab();
-                return title.equals(currentTab.getTitle());
+            public boolean onPostMessage(String message, Bundle extras) {
+                return true;
+            }
+
+            @Override
+            public boolean onNotifyMessageChannelReady(Bundle extras) {
+                // Now attempt to post a message.
+                Assert.assertTrue(
+                        getActivity().postMessage("New title") == CustomTabsService.RESULT_SUCCESS);
+                return true;
+            }
+
+            @Override
+            public void onDisconnectChannel(Context appContext) {}
+        });
+
+        Assert.assertTrue(getActivity().requestPostMessageChannel(FAKE_ORIGIN_URI));
+        // The callback registered above will post a message once the requested channel is ready.
+
+        waitForTitle("New title");
+    }
+
+    /**
+     * Tests the postMessage requests sent from the page is received on the client side.
+     */
+    @Test
+    @SmallTest
+    @EnableFeatures(ChromeFeatureList.CCT_MODULE_POST_MESSAGE)
+    public void testPostMessageReceivedFromPageByDynamicModule() throws Exception {
+        final CallbackHelper messageChannelHelper = new CallbackHelper();
+        final CallbackHelper onPostMessageHelper = new CallbackHelper();
+        final String url = mWebServer.setResponse("/test.html", MESSAGE_FROM_PAGE_TO_CHANNEL, null);
+
+        Context context = InstrumentationRegistry.getTargetContext();
+        Intent intent = CustomTabsTestUtils.createMinimalCustomTabIntent(context, url);
+        mCustomTabActivityTestRule.startCustomTabActivityWithIntent(intent);
+
+        ChromeTabUtils.waitForTabPageLoaded(getActivity().getActivityTab(), url);
+
+        getActivity().maybeInitialiseDynamicModulePostMessageHandler(new PostMessageBackend() {
+            @Override
+            public boolean onPostMessage(String message, Bundle extras) {
+                onPostMessageHelper.notifyCalled();
+                return true;
             }
+
+            @Override
+            public boolean onNotifyMessageChannelReady(Bundle extras) {
+                messageChannelHelper.notifyCalled();
+                return true;
+            }
+
+            @Override
+            public void onDisconnectChannel(Context appContext) {}
         });
+
+        Assert.assertTrue(getActivity().requestPostMessageChannel(FAKE_ORIGIN_URI));
+        messageChannelHelper.waitForCallback();
+        onPostMessageHelper.waitForCallback();
+    }
+
+    /**
+     * Tests the postMessage requests sent from the page is received on the client side.
+     */
+    @Test
+    @SmallTest
+    @EnableFeatures(ChromeFeatureList.CCT_MODULE_POST_MESSAGE)
+    public void testPostMessageFromDynamicModuleDisallowedBeforeModuleLoaded() throws Exception {
+        final CallbackHelper messageChannelHelper = new CallbackHelper();
+        final CallbackHelper onPostMessageHelper = new CallbackHelper();
+        final String url = mWebServer.setResponse("/test.html", MESSAGE_FROM_PAGE_TO_CHANNEL, null);
+
+        Context context = InstrumentationRegistry.getTargetContext();
+        Intent intent = CustomTabsTestUtils.createMinimalCustomTabIntent(context, url);
+        mCustomTabActivityTestRule.startCustomTabActivityWithIntent(intent);
+
+        ChromeTabUtils.waitForTabPageLoaded(getActivity().getActivityTab(), url);
+
+        // We shouldn't be able to open a channel or post messages yet.
+        Assert.assertFalse(getActivity().requestPostMessageChannel(FAKE_ORIGIN_URI));
+        Assert.assertTrue(getActivity().postMessage("Message")
+                == CustomTabsService.RESULT_FAILURE_DISALLOWED);
+
+        // Now fake initialisation of the dynamic module.
+        getActivity().maybeInitialiseDynamicModulePostMessageHandler(new PostMessageBackend() {
+            @Override
+            public boolean onPostMessage(String message, Bundle extras) {
+                onPostMessageHelper.notifyCalled();
+                return true;
+            }
+
+            @Override
+            public boolean onNotifyMessageChannelReady(Bundle extras) {
+                messageChannelHelper.notifyCalled();
+                return true;
+            }
+
+            @Override
+            public void onDisconnectChannel(Context appContext) {}
+        });
+
+        // We can now request a postMessage channel.
+        Assert.assertTrue(getActivity().requestPostMessageChannel(FAKE_ORIGIN_URI));
+    }
+
+    @Test
+    @SmallTest
+    @DisableFeatures(ChromeFeatureList.CCT_MODULE_POST_MESSAGE)
+    public void testPostMessageFromDynamicModuleDisallowedWhenFeatureDisabled() throws Exception {
+        final String url = mWebServer.setResponse("/test.html", MESSAGE_FROM_PAGE_TO_CHANNEL, null);
+
+        Context context = InstrumentationRegistry.getTargetContext();
+        Intent intent = CustomTabsTestUtils.createMinimalCustomTabIntent(context, url);
+        mCustomTabActivityTestRule.startCustomTabActivityWithIntent(intent);
+
+        ChromeTabUtils.waitForTabPageLoaded(getActivity().getActivityTab(), url);
+
+        // We shouldn't be able to open a channel or post messages yet.
+        Assert.assertFalse(getActivity().requestPostMessageChannel(FAKE_ORIGIN_URI));
+        Assert.assertTrue(getActivity().postMessage("Message")
+                == CustomTabsService.RESULT_FAILURE_DISALLOWED);
     }
 
     /**
@@ -2809,4 +2944,14 @@ public class CustomTabActivityTest {
         historyObserver.getQueryCallback().waitForCallback(0);
         return historyObserver.getHistoryQueryResults();
     }
+
+    private void waitForTitle(String newTitle) throws InterruptedException {
+        Tab currentTab = mCustomTabActivityTestRule.getActivity().getActivityTab();
+        TabTitleObserver titleObserver = new TabTitleObserver(currentTab, newTitle);
+        try {
+            titleObserver.waitForTitleUpdate(TITLE_UPDATE_TIMEOUT_MS);
+        } catch (TimeoutException e) {
+            fail("Tab title didn't update in time");
+        }
+    }
 }

chrome/browser/about_flags.cc

@@ -4191,6 +4191,9 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_WITH_PARAMS_VALUE_TYPE(chrome::android::kCCTModuleCache,
                                     kCCTModuleCacheVariations,
                                     "CCTModule")},
+    {"cct-module-post-message", flag_descriptions::kCCTModulePostMessageName,
+     flag_descriptions::kCCTModulePostMessageDescription, kOsAndroid,
+     FEATURE_VALUE_TYPE(chrome::android::kCCTModulePostMessage)},
 #endif
 
     {"enable-css-fragment-identifiers",

chrome/browser/android/chrome_feature_list.cc

@@ -83,6 +83,7 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &kCCTExternalLinkHandling,
     &kCCTModule,
     &kCCTModuleCache,
+    &kCCTModulePostMessage,
     &kCCTParallelRequest,
     &kCCTPostMessageAPI,
     &kCCTRedirectPreconnect,
@@ -225,6 +226,9 @@ const base::Feature kCCTModule{"CCTModule", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kCCTModuleCache{"CCTModuleCache",
                                     base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kCCTModulePostMessage{"CCTModulePostMessage",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kCCTParallelRequest{"CCTParallelRequest",
                                         base::FEATURE_ENABLED_BY_DEFAULT};
 

chrome/browser/android/chrome_feature_list.h

@@ -24,6 +24,7 @@ extern const base::Feature kCCTBackgroundTab;
 extern const base::Feature kCCTExternalLinkHandling;
 extern const base::Feature kCCTModule;
 extern const base::Feature kCCTModuleCache;
+extern const base::Feature kCCTModulePostMessage;
 extern const base::Feature kCCTParallelRequest;
 extern const base::Feature kCCTPostMessageAPI;
 extern const base::Feature kCCTRedirectPreconnect;

chrome/browser/flag_descriptions.cc

@@ -2305,6 +2305,12 @@ const char kCCTModuleCacheDescription[] =
     "Enables a cache for dynamically loaded modules in Chrome Custom Tabs. "
     "Under mild memory pressure the cache may be retained for some time";
 
+const char kCCTModulePostMessageName[] =
+    "Chrome Custom Tabs Module postMessage API";
+const char kCCTModulePostMessageDescription[] =
+    "Enables the postMessage API exposed to dynamically loaded modules in "
+    "Chrome Custom Tabs.";
+
 const char kChromeDuetName[] = "Chrome Duet";
 const char kChromeDuetDescription[] =
     "Enables Chrome Duet, split toolbar Chrome Home, on Android.";

chrome/browser/flag_descriptions.h

@@ -1391,6 +1391,9 @@ extern const char kCCTModuleDescription[];
 extern const char kCCTModuleCacheName[];
 extern const char kCCTModuleCacheDescription[];
 
+extern const char kCCTModulePostMessageName[];
+extern const char kCCTModulePostMessageDescription[];
+
 extern const char kChromeDuetName[];
 extern const char kChromeDuetDescription[];
 

tools/metrics/histograms/enums.xml

@@ -29584,6 +29584,7 @@ from previous Chrome versions.
       label="FramebustingNeedsSameOriginOrUserGesture:disabled"/>
   <int value="-1176493523" label="enable-md-extensions"/>
   <int value="-1174267639" label="ClientLoFi:disabled"/>
+  <int value="-1173361620" label="CCTModulePostMessage:disabled"/>
   <int value="-1172572865" label="NTPShowGoogleGInOmnibox:enabled"/>
   <int value="-1172204005" label="enable-offline-auto-reload-visible-only"/>
   <int value="-1167992523" label="DesktopPWAsCustomTabUI:disabled"/>
@@ -31049,6 +31050,7 @@ from previous Chrome versions.
   <int value="1589341623" label="disable-easy-unlock"/>
   <int value="1590278995"
       label="AutofillSendExperimentIdsInPaymentsRPCs:enabled"/>
+  <int value="1590300329" label="CCTModulePostMessage:enabled"/>
   <int value="1591653786" label="SpeculativePreconnect:enabled"/>
   <int value="1593720927" label="GamepadVibration:disabled"/>
   <int value="1593917165" label="SimplifiedNTP:disabled"/>