Reland "Query Tiles : Integration test"

This is a reland of d95d2248

Original change's description:
> Query Tiles : Integration test
> 
> This CL adds end-to-end Integration tests for query tiles. The network
> layer is substituted by a embedded test server that serves a fake
> server response. Added omnibox javatests that use this mechanism to
> test the full flow.
> 
> Bug: 1083807
> Change-Id: Ida65dd9e093ce2311def892158c6bbe4de1fe3c3
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2206153
> Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
> Reviewed-by: David Trainor <dtrainor@chromium.org>
> Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
> Reviewed-by: Hesen Zhang <hesen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#770512}

Bug: 1083807
Change-Id: I7f65bfb79006201bdaa545c0aba8dd7cf2b4a243
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2210654Reviewed-by: Xing Liu <xingliu@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Hesen Zhang <hesen@chromium.org>
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772139}

chrome/android/BUILD.gn

@@ -1732,6 +1732,7 @@ generate_jni("test_support_jni_headers") {
     "javatests/src/org/chromium/chrome/browser/offlinepages/OfflineTestUtil.java",
     "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchTestBridge.java",
     "javatests/src/org/chromium/chrome/browser/prerender/PrerenderTestHelper.java",
+    "javatests/src/org/chromium/chrome/browser/query_tiles/QueryTileFakeServer.java",
     "javatests/src/org/chromium/chrome/browser/test/MockCertVerifierRuleAndroid.java",
   ]
 }
@@ -1744,6 +1745,7 @@ android_library("browser_java_test_support") {
     "javatests/src/org/chromium/chrome/browser/offlinepages/OfflineTestUtil.java",
     "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchTestBridge.java",
     "javatests/src/org/chromium/chrome/browser/prerender/PrerenderTestHelper.java",
+    "javatests/src/org/chromium/chrome/browser/query_tiles/QueryTileFakeServer.java",
     "javatests/src/org/chromium/chrome/browser/sync/FakeServerHelper.java",
     "javatests/src/org/chromium/chrome/browser/test/MockCertVerifierRuleAndroid.java",
   ]
@@ -1772,13 +1774,17 @@ static_library("browser_test_support") {
     "../browser/offline_pages/android/offline_test_util_jni.cc",
     "../browser/offline_pages/android/prefetch_test_bridge.cc",
     "../browser/prerender/prerender_test_helper.cc",
+    "../browser/query_tiles/query_tile_fake_server.cc",
   ]
   deps = [
     ":test_support_jni_headers",
     "//chrome/browser",
     "//chrome/browser/thumbnail:test_support",
     "//components/offline_pages/core/background:test_support",
+    "//components/query_tiles",
+    "//components/query_tiles/test:test_support",
     "//content/test:test_support",
+    "//net:test_support",
   ]
 }
 

chrome/android/chrome_test_java_sources.gni

@@ -430,6 +430,7 @@ chrome_test_java_sources = [
   "javatests/src/org/chromium/chrome/browser/provider/ProviderTestRule.java",
   "javatests/src/org/chromium/chrome/browser/push_messaging/PushMessagingTest.java",
   "javatests/src/org/chromium/chrome/browser/query_tiles/ListMatchers.java",
+  "javatests/src/org/chromium/chrome/browser/query_tiles/OmniboxQueryTileSuggestionTest.java",
   "javatests/src/org/chromium/chrome/browser/query_tiles/QueryTileSectionTest.java",
   "javatests/src/org/chromium/chrome/browser/query_tiles/QueryTileSectionToOmniboxTest.java",
   "javatests/src/org/chromium/chrome/browser/query_tiles/TestTileProvider.java",

chrome/android/java/res/layout/omnibox_query_tiles_suggestion.xml

@@ -5,6 +5,7 @@
 
 <FrameLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/omnibox_query_tiles"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:padding="@dimen/card_padding">

chrome/android/javatests/src/org/chromium/chrome/browser/query_tiles/OmniboxQueryTileSuggestionTest.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.query_tiles;
+
+import static android.support.test.espresso.Espresso.onView;
+import static android.support.test.espresso.action.ViewActions.clearText;
+import static android.support.test.espresso.action.ViewActions.click;
+import static android.support.test.espresso.action.ViewActions.replaceText;
+import static android.support.test.espresso.assertion.ViewAssertions.doesNotExist;
+import static android.support.test.espresso.matcher.ViewMatchers.isDescendantOfA;
+import static android.support.test.espresso.matcher.ViewMatchers.withId;
+import static android.support.test.espresso.matcher.ViewMatchers.withParent;
+import static android.support.test.espresso.matcher.ViewMatchers.withText;
+
+import static org.chromium.chrome.browser.query_tiles.ListMatchers.matchList;
+import static org.chromium.chrome.browser.query_tiles.ViewActions.scrollTo;
+
+import android.support.test.filters.SmallTest;
+import android.view.View;
+import android.widget.TextView;
+
+import org.hamcrest.Matcher;
+import org.hamcrest.Matchers;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.base.task.PostTask;
+import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.flags.ChromeFeatureList;
+import org.chromium.chrome.browser.flags.ChromeSwitches;
+import org.chromium.chrome.browser.init.BrowserParts;
+import org.chromium.chrome.browser.init.ChromeBrowserInitializer;
+import org.chromium.chrome.browser.init.EmptyBrowserParts;
+import org.chromium.chrome.browser.omnibox.LocationBarLayout;
+import org.chromium.chrome.browser.omnibox.UrlBar;
+import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
+import org.chromium.chrome.test.ChromeTabbedActivityTestRule;
+import org.chromium.chrome.test.util.NewTabPageTestUtils;
+import org.chromium.chrome.test.util.OmniboxTestUtils;
+import org.chromium.chrome.test.util.browser.Features;
+import org.chromium.components.embedder_support.util.UrlConstants;
+import org.chromium.components.query_tiles.QueryTile;
+import org.chromium.components.query_tiles.TileProvider;
+import org.chromium.content_public.browser.UiThreadTaskTraits;
+import org.chromium.content_public.browser.test.util.Criteria;
+import org.chromium.content_public.browser.test.util.CriteriaHelper;
+import org.chromium.content_public.browser.test.util.TestThreadUtils;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Tests for the query tiles section on the omnibox. The test uses a fake server in native to
+ * perform a full end-to-end test for omnibox query tiles.
+ */
+@RunWith(ChromeJUnit4ClassRunner.class)
+@CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
+@Features.EnableFeatures({ChromeFeatureList.QUERY_TILES, ChromeFeatureList.QUERY_TILES_IN_OMNIBOX})
+public class OmniboxQueryTileSuggestionTest {
+    private static final String SEARCH_URL_PATTERN = "https://www.google.com/search?q=";
+
+    @Rule
+    public ChromeTabbedActivityTestRule mActivityTestRule = new ChromeTabbedActivityTestRule();
+
+    private Tab mTab;
+    private UrlBar mUrlBar;
+    private LocationBarLayout mLocationBar;
+
+    // A convenient wrapper around the real provider, used for matching purposes.
+    private TestTileProvider mTileProvider;
+
+    @Before
+    public void setUp() {
+        loadNative();
+        final AtomicBoolean tilesFetched = new AtomicBoolean();
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            QueryTileFakeServer.setupFakeServer(2, 4, success -> tilesFetched.set(true));
+        });
+        mActivityTestRule.startMainActivityOnBlankPage();
+        mActivityTestRule.loadUrl(UrlConstants.NTP_URL);
+        mTab = mActivityTestRule.getActivity().getActivityTab();
+        NewTabPageTestUtils.waitForNtpLoaded(mTab);
+
+        CriteriaHelper.pollUiThread(tilesFetched::get, "Tile fetch was not completed.");
+
+        // Accessing profile needs UI thread.
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            TileProvider realProvider =
+                    TileProviderFactory.getForProfile(Profile.getLastUsedRegularProfile());
+            mTileProvider = new TestTileProvider(realProvider);
+        });
+
+        mUrlBar = (UrlBar) mActivityTestRule.getActivity().findViewById(R.id.url_bar);
+        mLocationBar =
+                (LocationBarLayout) mActivityTestRule.getActivity().findViewById(R.id.location_bar);
+    }
+
+    @After
+    public void tearDown() {}
+
+    /** Tests that tiles show up as expected when omnibox is opened. */
+    @Test
+    @SmallTest
+    public void testShowOmniboxQueryTileSuggestion() throws Exception {
+        clickNTPSearchBox();
+        OmniboxTestUtils.waitForFocusAndKeyboardActive(mUrlBar, true);
+        OmniboxTestUtils.waitForOmniboxSuggestions(mLocationBar);
+
+        Matcher<View> recyclerViewMatcher = withParent(withId(R.id.omnibox_query_tiles));
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf());
+    }
+
+    /** Tests that clicking on a tile opens up the next level tiles in omnibox. */
+    @Test
+    @SmallTest
+    public void testClickTileOpensNextTierTiles() throws Exception {
+        clickNTPSearchBox();
+        OmniboxTestUtils.waitForFocusAndKeyboardActive(mUrlBar, true);
+        OmniboxTestUtils.waitForOmniboxSuggestions(mLocationBar);
+
+        Matcher<View> recyclerViewMatcher = withParent(withId(R.id.omnibox_query_tiles));
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf());
+
+        // Click a tile. Suggestion with next level tiles should show up, and omnibox should show
+        // query text from the tile.
+        QueryTile tile = mTileProvider.getTileAt(0);
+        onView(recyclerViewMatcher).perform(scrollTo(0));
+        onView(tileSuggestionMatcher(tile)).perform(click());
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf(0));
+        Assert.assertTrue(mUrlBar.getText().toString().contains(tile.queryText));
+    }
+
+    /** Tests that clicking on a tile hides the suggestion and shows the query on omnibox. */
+    @Test
+    @SmallTest
+    @Features.EnableFeatures(ChromeFeatureList.QUERY_TILES_ENABLE_QUERY_EDITING)
+    public void testClickTileOpensQueryEditMode() throws Exception {
+        clickNTPSearchBox();
+        OmniboxTestUtils.waitForFocusAndKeyboardActive(mUrlBar, true);
+        OmniboxTestUtils.waitForOmniboxSuggestions(mLocationBar);
+
+        Matcher<View> recyclerViewMatcher = withParent(withId(R.id.omnibox_query_tiles));
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf());
+
+        // Click the first level tile.
+        QueryTile tile = mTileProvider.getTileAt(0);
+        QueryTile subtile = mTileProvider.getTileAt(0, 0);
+        onView(recyclerViewMatcher).perform(scrollTo(0));
+        onView(tileSuggestionMatcher(tile)).perform(click());
+
+        // Click the last level tile. The omnibox should show the query text. No suggestions should
+        // show up.
+        Assert.assertTrue(mUrlBar.getText().toString().contains(tile.queryText));
+        onView(recyclerViewMatcher).perform(scrollTo(0));
+        onView(tileSuggestionMatcher(subtile)).perform(click());
+        Assert.assertTrue(mUrlBar.getText().toString().contains(subtile.queryText));
+        onView(recyclerViewMatcher).check(doesNotExist());
+    }
+
+    /** Tests that clicking a last level tile loads the search result page. */
+    @Test
+    @SmallTest
+    public void testClickLastLevelTileOpensSearchResultsPage() throws Exception {
+        clickNTPSearchBox();
+        OmniboxTestUtils.waitForFocusAndKeyboardActive(mUrlBar, true);
+        OmniboxTestUtils.waitForOmniboxSuggestions(mLocationBar);
+
+        Matcher<View> recyclerViewMatcher = withParent(withId(R.id.omnibox_query_tiles));
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf());
+
+        // Click twice to get to the search results page.
+        QueryTile tile = mTileProvider.getTileAt(0);
+        QueryTile subtile = mTileProvider.getTileAt(0, 0);
+        onView(recyclerViewMatcher).perform(scrollTo(0));
+        onView(tileSuggestionMatcher(tile)).perform(click());
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf(0));
+        Assert.assertTrue(mUrlBar.getText().toString().contains(tile.queryText));
+
+        onView(recyclerViewMatcher).perform(scrollTo(0));
+        onView(tileSuggestionMatcher(subtile)).perform(click());
+        waitForSearchResultsPage();
+        Assert.assertTrue(getTabUrl().contains(subtile.queryText));
+        onView(recyclerViewMatcher).check(doesNotExist());
+    }
+
+    /** Tests that typing on omnibox will dismiss the query tiles suggestion. */
+    @Test
+    @SmallTest
+    public void testTypingInOmniboxDismissesQueryTileSuggestion() throws Exception {
+        clickNTPSearchBox();
+        OmniboxTestUtils.waitForFocusAndKeyboardActive(mUrlBar, true);
+        OmniboxTestUtils.waitForOmniboxSuggestions(mLocationBar);
+
+        Matcher<View> recyclerViewMatcher = withParent(withId(R.id.omnibox_query_tiles));
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf());
+
+        QueryTile tile = mTileProvider.getTileAt(0);
+        onView(recyclerViewMatcher).perform(scrollTo(0));
+        onView(tileSuggestionMatcher(tile)).perform(click());
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf(0));
+        Assert.assertTrue(mUrlBar.getText().toString().contains(tile.queryText));
+
+        // Start editing the text. The query tile suggestion should disappear.
+        onView(withId(R.id.url_bar)).perform(replaceText("xyz"));
+        waitForOmniboxQueryTileSuggestion(false);
+
+        // Backspace all the way to zero suggest. The query tile suggestion should reappear.
+        onView(withId(R.id.url_bar)).perform(clearText());
+        matchList(recyclerViewMatcher, mTileProvider.getChildrenOf());
+    }
+
+    private Matcher<View> tileSuggestionMatcher(QueryTile tile) {
+        Matcher<View> recyclerViewMatcher = withParent(withId(R.id.omnibox_query_tiles));
+        return Matchers.allOf(isDescendantOfA(recyclerViewMatcher), withText(tile.displayTitle));
+    }
+
+    private void clickNTPSearchBox() {
+        // Directly clicking search box using espresso doesn't work and seems to forward the click
+        // event to the chip cancel button instead.
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            TextView searchBox =
+                    (TextView) mActivityTestRule.getActivity().findViewById(R.id.search_box_text);
+            searchBox.performClick();
+        });
+    }
+
+    private String getTabUrl() {
+        return mActivityTestRule.getActivity().getActivityTab().getUrl().getValidSpecOrEmpty();
+    }
+
+    private void waitForOmniboxQueryTileSuggestion(boolean visible) {
+        CriteriaHelper.pollUiThread(new Criteria(
+                "The omnibox query tile suggestion didn't match the expected visibility: "
+                + visible) {
+            @Override
+            public boolean isSatisfied() {
+                View view = mActivityTestRule.getActivity().findViewById(R.id.omnibox_query_tiles);
+                boolean isVisible = view != null && view.getVisibility() == View.VISIBLE;
+                return isVisible == visible;
+            }
+        });
+    }
+
+    private void waitForSearchResultsPage() {
+        CriteriaHelper.pollUiThread(
+                new Criteria("The SRP was never loaded. " + mTab.getUrl().getValidSpecOrEmpty()) {
+                    @Override
+                    public boolean isSatisfied() {
+                        return mTab.getUrl().getValidSpecOrEmpty().contains(SEARCH_URL_PATTERN);
+                    }
+                });
+    }
+
+    private void loadNative() {
+        final AtomicBoolean mNativeLoaded = new AtomicBoolean();
+        final BrowserParts parts = new EmptyBrowserParts() {
+            @Override
+            public void finishNativeInitialization() {
+                mNativeLoaded.set(true);
+            }
+        };
+        PostTask.postTask(UiThreadTaskTraits.DEFAULT, () -> {
+            ChromeBrowserInitializer.getInstance().handlePreNativeStartup(parts);
+            ChromeBrowserInitializer.getInstance().handlePostNativeStartup(true, parts);
+        });
+        CriteriaHelper.pollUiThread(
+                () -> mNativeLoaded.get(), "Failed while waiting for starting native.");
+    }
+}

chrome/android/javatests/src/org/chromium/chrome/browser/query_tiles/QueryTileFakeServer.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.query_tiles;
+
+import org.chromium.base.Callback;
+
+/**
+ * Spins up a test server and starts serving query tiles in native.
+ */
+public class QueryTileFakeServer {
+    /**
+     * Spins up a test server and starts serving query tiles in native. Should be invoked after
+     * native initialization and before rest of the chrome and omnibox is loaded.
+     * @param levels The number of levels of query tiles.
+     * @param tilesPerLevel The number of tiles in each level.
+     * @param onFetchCompletedCallback The callback to be invoked after server fetch is complete.
+     */
+    public static void setupFakeServer(
+            int levels, int tilesPerLevel, Callback<Boolean> onFetchCompletedCallback) {
+        nativeSetupFakeServer(onFetchCompletedCallback, levels, tilesPerLevel);
+    }
+
+    static native void nativeSetupFakeServer(
+            Callback<Boolean> onFetchCompletedCallback, int levels, int tilesPerLevel);
+}
\ No newline at end of file

chrome/android/javatests/src/org/chromium/chrome/browser/query_tiles/TestTileProvider.java

@@ -28,6 +28,14 @@ class TestTileProvider implements TileProvider {
         mTiles = buildTiles("Tile", levels, count);
     }
 
+    /**
+     * Builds and populates a {@link TestTileProvider} around the real provider. Convenient for
+     * matching purposes.
+     */
+    public TestTileProvider(TileProvider realProvider) {
+        realProvider.getQueryTiles(tiles -> { mTiles = tiles; });
+    }
+
     /**
      * Finds a tile by traversing the tree.
      * @param indices The indices for each child to select as the tree is traversed.
@@ -75,4 +83,4 @@ class TestTileProvider implements TileProvider {
 
         return children;
     }
-}
\ No newline at end of file
+}

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

@@ -352,6 +352,7 @@ public abstract class ChromeFeatureList {
     public static final String PRIORITIZE_BOOTSTRAP_TASKS = "PrioritizeBootstrapTasks";
     public static final String PROBABILISTIC_CRYPTID_RENDERER = "ProbabilisticCryptidRenderer";
     public static final String QUERY_TILES = "QueryTiles";
+    public static final String QUERY_TILES_IN_OMNIBOX = "QueryTilesInOmnibox";
     public static final String QUERY_TILES_ENABLE_QUERY_EDITING = "QueryTilesEnableQueryEditing";
     public static final String QUERY_IN_OMNIBOX = "QueryInOmnibox";
     public static final String QUIET_NOTIFICATION_PROMPTS = "QuietNotificationPrompts";

chrome/browser/query_tiles/query_tile_fake_server.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/android/callback_android.h"
+#include "base/android/jni_android.h"
+#include "base/android/scoped_java_ref.h"
+#include "chrome/android/test_support_jni_headers/QueryTileFakeServer_jni.h"
+#include "chrome/browser/android/profile_key_util.h"
+#include "chrome/browser/profiles/profile_key.h"
+#include "chrome/browser/query_tiles/tile_service_factory.h"
+#include "components/query_tiles/switches.h"
+#include "components/query_tiles/test/fake_server_response.h"
+#include "net/test/embedded_test_server/embedded_test_server.h"
+#include "net/test/embedded_test_server/http_request.h"
+#include "net/test/embedded_test_server/http_response.h"
+
+using base::android::JavaParamRef;
+using base::android::ScopedJavaGlobalRef;
+using net::test_server::EmbeddedTestServer;
+using net::test_server::HttpRequest;
+using net::test_server::HttpResponse;
+
+namespace {
+
+// An instance of test server responding with the required fake tiles.
+static std::unique_ptr<EmbeddedTestServer> s_embedded_test_server;
+
+std::unique_ptr<net::test_server::HttpResponse> HandleRequest(
+    int levels,
+    int tiles_per_level,
+    const net::test_server::HttpRequest& request) {
+  auto response = std::make_unique<net::test_server::BasicHttpResponse>();
+  response->set_code(net::HTTP_OK);
+  std::string proto =
+      query_tiles::FakeServerResponse::CreateServerResponseProto(
+          levels, tiles_per_level);
+  response->set_content(proto);
+  return std::move(response);
+}
+
+void OnTilesFetched(const ScopedJavaGlobalRef<jobject>& j_callback,
+                    bool success) {
+  base::android::RunBooleanCallbackAndroid(j_callback, success);
+}
+
+}  // namespace
+
+JNI_EXPORT void JNI_QueryTileFakeServer_SetupFakeServer(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& j_callback,
+    jint levels,
+    jint tiles_per_level) {
+  s_embedded_test_server = std::make_unique<EmbeddedTestServer>();
+  s_embedded_test_server->RegisterRequestHandler(
+      base::BindRepeating(&HandleRequest, levels, tiles_per_level));
+  DCHECK(s_embedded_test_server->Start());
+  GURL url = s_embedded_test_server->GetURL("/fake_server_url");
+  query_tiles::FakeServerResponse::SetTileFetcherServerURL(url);
+
+  auto* profile_key = android::GetLastUsedRegularProfileKey();
+  query_tiles::TileService* tile_service =
+      query_tiles::TileServiceFactory::GetInstance()->GetForKey(profile_key);
+  tile_service->StartFetchForTiles(
+      false, base::BindOnce(&OnTilesFetched,
+                            ScopedJavaGlobalRef<jobject>(j_callback)));
+}

components/query_tiles/internal/tile_fetcher.cc

@@ -6,6 +6,7 @@
 
 #include <utility>
 
+#include "base/lazy_instance.h"
 #include "components/query_tiles/internal/stats.h"
 #include "net/base/url_util.h"
 #include "net/http/http_request_headers.h"
@@ -18,6 +19,9 @@
 namespace query_tiles {
 namespace {
 
+// An override server URL for testing.
+base::LazyInstance<GURL>::Leaky g_override_url_for_testing;
+
 const char kRequestContentType[] = "application/x-protobuf";
 
 constexpr net::NetworkTrafficAnnotationTag kQueryTilesFetcherTrafficAnnotation =
@@ -94,6 +98,10 @@ class TileFetcherImpl : public TileFetcher {
       request->headers.SetHeader(net::HttpRequestHeaders::kAcceptLanguage,
                                  accept_languages_);
     }
+
+    if (!g_override_url_for_testing.Get().is_empty())
+      request->url = g_override_url_for_testing.Get();
+
     return request;
   }
 
@@ -175,6 +183,11 @@ std::unique_ptr<TileFetcher> TileFetcher::Create(
                                            client_version, url_loader_factory);
 }
 
+// static
+void TileFetcher::SetOverrideURLForTesting(const GURL& url) {
+  g_override_url_for_testing.Get() = url;
+}
+
 TileFetcher::TileFetcher() = default;
 TileFetcher::~TileFetcher() = default;
 

components/query_tiles/internal/tile_fetcher.h

@@ -39,6 +39,9 @@ class TileFetcher {
       const std::string& client_version,
       const scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory);
 
+  // For testing only.
+  static void SetOverrideURLForTesting(const GURL& url);
+
   // Start the fetch to download tiles.
   virtual void StartFetchForTiles(FinishedCallback callback) = 0;
 

components/query_tiles/test/BUILD.gn

@@ -6,11 +6,17 @@ source_set("test_support") {
   testonly = true
 
   sources = [
+    "fake_server_response.cc",
+    "fake_server_response.h",
     "fake_tile_service.cc",
     "fake_tile_service.h",
   ]
 
-  deps = [ "//components/query_tiles:public" ]
+  deps = [
+    "//components/query_tiles:public",
+    "//components/query_tiles/internal",
+    "//components/query_tiles/proto",
+  ]
 }
 
 source_set("test_lib") {

components/query_tiles/test/fake_server_response.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/query_tiles/test/fake_server_response.h"
+
+#include "base/strings/string_number_conversions.h"
+#include "components/query_tiles/internal/tile_fetcher.h"
+#include "components/query_tiles/proto/tile_response.pb.h"
+
+namespace query_tiles {
+namespace {
+
+constexpr char kTestLocale[] = "en";
+
+std::string BuildPrefix(const std::string& prefix, size_t pos) {
+  return prefix + "_" + base::NumberToString(pos);
+}
+
+void CreateTiles(proto::TileInfoGroup* info_group,
+                 proto::TileInfo* parent,
+                 const std::string& prefix,
+                 int levels,
+                 size_t tiles_per_level) {
+  if (levels <= 0)
+    return;
+
+  // Add sub-tiles.
+  for (size_t j = 0; j < tiles_per_level; j++) {
+    std::string subprefix = BuildPrefix(prefix, j);
+    parent->add_sub_tile_ids(subprefix + "_id");
+    auto* new_tile = info_group->add_tiles();
+    new_tile->set_tile_id(subprefix + "_id");
+    new_tile->set_display_text(subprefix + "_display_text");
+    new_tile->set_accessibility_text(subprefix + "_accessibility_text");
+    new_tile->set_query_string(subprefix + "_query_string");
+    new_tile->set_is_top_level(false);
+
+    // Add sub-tiles.
+    CreateTiles(info_group, new_tile, subprefix, levels - 1, tiles_per_level);
+  }
+}
+
+// Build a fake two level response proto.
+void InitResponseProto(proto::ServerResponse* response,
+                       int levels,
+                       size_t tiles_per_level) {
+  proto::TileInfoGroup* info_group = response->mutable_tile_group();
+  info_group->set_locale(kTestLocale);
+  // Add top level tiles.
+  for (size_t i = 0; i < tiles_per_level; i++) {
+    auto* new_top_level_tile = info_group->add_tiles();
+    std::string prefix = BuildPrefix("Tile", i);
+    new_top_level_tile->set_tile_id(prefix + "_id");
+    new_top_level_tile->set_display_text(prefix + "_display_text");
+    new_top_level_tile->set_accessibility_text(prefix + "_accessibility_text");
+    new_top_level_tile->set_query_string(prefix + "_query_string");
+    new_top_level_tile->set_is_top_level(true);
+
+    // Add sub-tiles.
+    CreateTiles(info_group, new_top_level_tile, prefix, levels - 1,
+                tiles_per_level);
+  }
+}
+
+}  // namespace
+
+// static
+void FakeServerResponse::SetTileFetcherServerURL(const GURL& url) {
+  TileFetcher::SetOverrideURLForTesting(url);
+}
+
+// static
+std::string FakeServerResponse::CreateServerResponseProto(int levels,
+                                                          int tiles_per_level) {
+  proto::ServerResponse server_response;
+  InitResponseProto(&server_response, levels, tiles_per_level);
+
+  std::string response_str;
+  DCHECK(server_response.SerializeToString(&response_str));
+  return response_str;
+}
+
+}  // namespace query_tiles

components/query_tiles/test/fake_server_response.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_QUERY_TILES_TEST_FAKE_SERVER_RESPONSE_H_
+#define COMPONENTS_QUERY_TILES_TEST_FAKE_SERVER_RESPONSE_H_
+
+#include <memory>
+#include <string>
+
+#include "url/gurl.h"
+
+namespace query_tiles {
+
+// This class provides the necessary utilities that can be used to fake the
+// query tiles server interaction for using in tests.
+class FakeServerResponse {
+ public:
+  // Sets the query tile server endpoint to the given |url|.
+  static void SetTileFetcherServerURL(const GURL& url);
+
+  // Creates a fake server response proto, which has |levels| tiers, and each
+  // tier has |tiles_per_level| tiles.
+  static std::string CreateServerResponseProto(int levels, int tiles_per_level);
+};
+
+}  // namespace query_tiles
+
+#endif  // COMPONENTS_QUERY_TILES_TEST_FAKE_SERVER_RESPONSE_H_