Add ContextualSuggestionsService to Omnibox

components/omnibox/browser/contextual_suggestions_service.cc

Index: components/omnibox/browser/contextual_suggestions_service.cc
diff --git a/components/omnibox/browser/contextual_suggestions_service.cc b/components/omnibox/browser/contextual_suggestions_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..dbae158a03a33cd66cb580ab4f78db82eaf77db5
--- /dev/null
+++ b/components/omnibox/browser/contextual_suggestions_service.cc
@@ -0,0 +1,266 @@
+// Copyright 2017 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/omnibox/browser/contextual_suggestions_service.h"
+
+#include "base/feature_list.h"
+#include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial_params.h"
+#include "base/strings/stringprintf.h"
+#include "components/data_use_measurement/core/data_use_user_data.h"
+#include "components/omnibox/browser/omnibox_field_trial.h"
+#include "components/variations/net/variations_http_headers.h"
+#include "net/base/escape.h"
+#include "net/base/load_flags.h"
+#include "net/http/http_response_headers.h"
+#include "net/traffic_annotation/network_traffic_annotation.h"
+#include "net/url_request/url_fetcher.h"
+
+namespace contextual_suggestions {
+
+namespace {
+// Server address for the experimental suggestions service.
+const char kExperimentalServerAddress[] =
+    "https://cuscochromeextension-pa.googleapis.com/v1/zerosuggestions";
+
+// Parameter name used by the experiment redirecting Zero Suggestion requests
+// to a service provided by the Chrome team.
+const char kZeroSuggestRedirectToChromeExperimentIdParam[] =
+    "ZeroSuggestRedirectToChromeExperimentID";
+
+// Scope for the authentication token attached to the request sent to the
+// experimental service.
+const char kScopeForExperimentalService[] =
+    "https://www.googleapis.com/auth/cusco-chrome-extension";
+
+// Format string for OAuth2 authentication headers.
+const char kAuthorizationHeaderFormat[] = "Authorization: Bearer %s";
+
+}  // namespace
+
+ContextualSuggestionsService::ContextualSuggestionsService(
+    SigninManagerBase* signin_manager,
+    OAuth2TokenService* token_service,
+    TemplateURLService* template_url_service,
+    net::URLRequestContextGetter* request_context)
+    : request_context_(request_context),
+      signin_manager_(signin_manager),
+      template_url_service_(template_url_service),
+      token_service_(token_service) {}
+
+ContextualSuggestionsService::~ContextualSuggestionsService() {}
+
+bool ContextualSuggestionsService::UseExperimentalZeroSuggestSuggestions(
+    const std::string& visited_url) const {
+  if (visited_url.empty()) {
+    return false;
+  }
+
+  if (!base::FeatureList::IsEnabled(omnibox::kZeroSuggestRedirectToChrome) ||
+      template_url_service_ == nullptr) {
+    return false;
+  }
+
+  // Check that the default search engine is Google.
+  const TemplateURL& default_provider_url =
+      *template_url_service_->GetDefaultSearchProvider();
+  const SearchTermsData& search_terms_data =
+      template_url_service_->search_terms_data();
+  if (default_provider_url.GetEngineType(search_terms_data) !=
+      SEARCH_ENGINE_GOOGLE) {
+    return false;
+  }
+
+  // Check that the suggest URL for redirect to chrome field trial is valid.
+  const GURL suggest_url =
+      ExperimentalZeroSuggestURL(/*visited_url=*/std::string());

[Mark P, 2017/07/18 19:11:28]

Shouldn't you provide a real URL here?  I wouldn't be surprised if
ExperimentalZeroSuggestURL rejects constructing a suggestion URL if the provided
context URL is invalid.

[Toyama, 2017/07/18 20:28:47]

I don't have the right context here, but everything seems to be working just
fine with or without current_url. I agree with you that it's probably better to
pass something than an empty string.

+  if (!suggest_url.is_valid()) {
+    return false;
+  }
+
+  // Check that the suggest URL for redirect to chrome is HTTPS.
+  return suggest_url.SchemeIsCryptographic();
+}
+
+void ContextualSuggestionsService::CreateContextualSuggestionsRequest(
+    const std::string& visited_url,
+    net::URLFetcherDelegate* fetcher_delegate,
+    ContextualSuggestionsCallback callback) {
+  DCHECK(signin_manager_);
+  DCHECK(token_service_);
+
+  const bool experimental = UseExperimentalZeroSuggestSuggestions(visited_url);
+  std::unique_ptr<net::URLFetcher> fetcher =
+      CreateRequest(visited_url, experimental, fetcher_delegate);
+  if (fetcher == nullptr) {
+    std::move(callback).Run(nullptr);
+    return;
+  }
+
+  if (experimental) {
+    // Skip this request if still waiting for oauth2 token.
+    if (token_fetcher_) {
+      std::move(callback).Run(nullptr);
+      return;
+    }
+    // Create the oauth2 token fetcher.
+    OAuth2TokenService::ScopeSet scopes{kScopeForExperimentalService};
+    token_fetcher_ = base::MakeUnique<AccessTokenFetcher>(
+        "contextual_suggestions_service", signin_manager_, token_service_,
+        scopes,
+        base::BindOnce(&ContextualSuggestionsService::AccessTokenAvailable,
+                       base::Unretained(this), std::move(fetcher),
+                       std::move(callback)));
+    return;
+  }
+
+  std::move(callback).Run(std::move(fetcher));
+}
+
+// static
+GURL ContextualSuggestionsService::ExperimentalZeroSuggestURL(
+    const std::string& visited_url) {
+  const std::string server_address(kExperimentalServerAddress);
+  const int experiment_id = base::GetFieldTrialParamByFeatureAsInt(
+      omnibox::kZeroSuggestRedirectToChrome,
+      kZeroSuggestRedirectToChromeExperimentIdParam, /*default_value=*/-1);
+  const std::string additional_parameters =
+      experiment_id >= 0
+          ? base::StringPrintf("&experiment_id=%d", experiment_id)
+          : "&";
+  return GURL(server_address + "/url=" + net::EscapePath(visited_url) +
+              additional_parameters);
+}
+
+GURL ContextualSuggestionsService::ZeroSuggestURL(
+    const std::string& visited_url,
+    bool experimental) const {
+  if (experimental) {
+    return ExperimentalZeroSuggestURL(visited_url);
+  }
+
+  const TemplateURLRef& suggestion_url_ref =
+      template_url_service_->GetDefaultSearchProvider()->suggestions_url_ref();
+  const SearchTermsData& search_terms_data =
+      template_url_service_->search_terms_data();
+  base::string16 prefix;
+  TemplateURLRef::SearchTermsArgs search_term_args(prefix);
+  if (!visited_url.empty()) {
+    search_term_args.current_page_url = visited_url;
+  }
+  return GURL(suggestion_url_ref.ReplaceSearchTerms(search_term_args,
+                                                    search_terms_data));
+}
+
+std::unique_ptr<net::URLFetcher> ContextualSuggestionsService::CreateRequest(
+    const std::string& visited_url,
+    bool experimental,
+    net::URLFetcherDelegate* fetcher_delegate) const {
+  const GURL suggest_url = ZeroSuggestURL(visited_url, experimental);
+  DCHECK(suggest_url.is_valid());
+
+  if (visited_url.empty())
+    experimental = false;
+  const int kFetcherID = 1;
+  net::NetworkTrafficAnnotationTag annotation_tag =
+      experimental
+          ? net::DefineNetworkTrafficAnnotation(
+                "omnibox_zerosuggest_experimental", R"(
+        semantics {
+          sender: "Omnibox"
+          description:
+            "When the user focuses the omnibox, Chrome can provide search or "
+            "navigation suggestions from the default search provider in the "
+            "omnibox dropdown, based on the current page URL.\n"
+            "This is limited to users whose default search engine is Google, "
+            "as no other search engines currently support this kind of "
+            "suggestion."
+          trigger: "The omnibox receives focus."
+          data: "The user's OAuth2 credentials and the URL of the current page."
+          destination: GOOGLE_OWNED_SERVICE
+        }
+        policy {
+          cookies_allowed: false
+          setting:
+            "Users can control this feature via the 'Use a prediction service "
+            "to help complete searches and URLs typed in the address bar' "
+            "settings under 'Privacy'. The feature is enabled by default."
+          chrome_policy {
+            SearchSuggestEnabled {
+                policy_options {mode: MANDATORY}
+                SearchSuggestEnabled: false
+            }
+          }
+        })")
+          : net::DefineNetworkTrafficAnnotation("omnibox_zerosuggest", R"(
+        semantics {
+          sender: "Omnibox"
+          description:
+            "When the user focuses the omnibox, Chrome can provide search or "
+            "navigation suggestions from the default search provider in the "
+            "omnibox dropdown, based on the current page URL.\n"
+            "This is limited to users whose default search engine is Google, "
+            "as no other search engines currently support this kind of "
+            "suggestion."
+          trigger: "The omnibox receives focus."
+          data: "The URL of the current page."
+          destination: GOOGLE_OWNED_SERVICE
+        }
+        policy {
+          cookies_allowed: true
+          cookies_store: "user"
+          setting:
+            "Users can control this feature via the 'Use a prediction service "
+            "to help complete searches and URLs typed in the address bar' "
+            "settings under 'Privacy'. The feature is enabled by default."
+          chrome_policy {
+            SearchSuggestEnabled {
+                policy_options {mode: MANDATORY}
+                SearchSuggestEnabled: false
+            }
+          }
+        })");
+
+  std::unique_ptr<net::URLFetcher> fetcher =
+      net::URLFetcher::Create(kFetcherID, suggest_url, net::URLFetcher::GET,
+                              fetcher_delegate, annotation_tag);
+  fetcher->SetRequestContext(request_context_);
+  if (experimental) {
+    fetcher->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
+                          net::LOAD_DO_NOT_SAVE_COOKIES);
+  } else {
+    data_use_measurement::DataUseUserData::AttachToFetcher(
+        fetcher.get(), data_use_measurement::DataUseUserData::OMNIBOX);
+    fetcher->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES);
+    // Add Chrome experiment state to the request headers.
+    net::HttpRequestHeaders headers;
+    // Note: It's OK to pass |is_signed_in| false if it's unknown, as it does
+    // not affect transmission of experiments coming from the variations server.
+    variations::AppendVariationHeaders(fetcher->GetOriginalURL(), false, false,
+                                       /*is_signed_in=*/false, &headers);
+    fetcher->SetExtraRequestHeaders(headers.ToString());
+  }
+  return fetcher;
+}
+
+void ContextualSuggestionsService::AccessTokenAvailable(
+    std::unique_ptr<net::URLFetcher> fetcher,
+    ContextualSuggestionsCallback callback,
+    const GoogleServiceAuthError& error,
+    const std::string& access_token) {
+  DCHECK(token_fetcher_);
+  std::unique_ptr<AccessTokenFetcher> token_fetcher_deleter(
+      std::move(token_fetcher_));
+
+  if (error.state() != GoogleServiceAuthError::NONE) {
+    std::move(callback).Run(nullptr);
+    return;
+  }
+  DCHECK(!access_token.empty());
+  fetcher->AddExtraRequestHeader(
+      base::StringPrintf(kAuthorizationHeaderFormat, access_token.c_str()));
+  std::move(callback).Run(std::move(fetcher));
+}
+
+}  // namespace contextual_suggestions