Added new adaptive "Suggest" tab on the New Tab Page, behing the flag, for the experiments.

chrome/browser/ui/webui/ntp/suggested_page_handler.cc

+// Copyright (c) 2012 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 "chrome/browser/ui/webui/ntp/suggested_page_handler.h"
+
+#include <set>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/command_line.h"
+#include "base/md5.h"
+#include "base/memory/scoped_vector.h"
+#include "base/memory/singleton.h"
+#include "base/string16.h"
+#include "base/string_number_conversions.h"
+#include "base/threading/thread.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
+#include "chrome/browser/history/page_usage_data.h"
+#include "chrome/browser/history/top_sites.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/scoped_user_pref_update.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/webui/chrome_url_data_manager.h"
+#include "chrome/browser/ui/webui/favicon_source.h"
+#include "chrome/browser/ui/webui/ntp/new_tab_ui.h"
+#include "chrome/browser/ui/webui/ntp/thumbnail_source.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/common/url_constants.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_source.h"
+#include "content/public/browser/user_metrics.h"
+#include "content/public/browser/web_ui.h"
+#include "googleurl/src/gurl.h"
+#include "grit/chromium_strings.h"
+#include "grit/generated_resources.h"
+#include "grit/locale_settings.h"
+#include "ui/base/l10n/l10n_util.h"
+
+using content::UserMetricsAction;
+
+SuggestedHandler::SuggestedHandler()
+    : got_first_suggested_request_(false) {
+}
+
+SuggestedHandler::~SuggestedHandler() {
+}
+
+void SuggestedHandler::RegisterMessages() {
+  Profile* profile = Profile::FromWebUI(web_ui());
+  // Set up our sources for thumbnail and favicon data.
+  ThumbnailSource* thumbnail_src = new ThumbnailSource(profile);
+  profile->GetChromeURLDataManager()->AddDataSource(thumbnail_src);

[Dan Beam, 2012/02/09 01:43:06]

nit: make look like line below

[GeorgeY, 2012/02/10 00:00:36]

Done.

+

[Dan Beam, 2012/02/09 01:43:06]

nit: remove newline

[GeorgeY, 2012/02/10 00:00:36]

Done.

+  profile->GetChromeURLDataManager()->AddDataSource(
+      new FaviconSource(profile, FaviconSource::FAVICON));
+
+  // TODO(georgey) change it to provide our data.

[Dan Beam, 2012/02/09 01:43:06]

nit: Capitalize and describe what "it" means in this context (like by replacing
it with a noun, not pronoun) here and through out (the other 3 or 4
occurrences).

[GeorgeY, 2012/02/10 00:00:36]

Done.

+  history::TopSites* ts = profile->GetTopSites();

[Dan Beam, 2012/02/09 01:43:06]

nit: ts could be thumbnail source, make more descriptive var name

[GeorgeY, 2012/02/10 00:00:36]

Done.

+  if (ts) {
+    // TopSites updates itself after a delay. This is especially noticable when
+    // your profile is empty. Ask TopSites to update itself when we're about to
+    // show the new tab page.
+    ts->SyncWithHistory();
+
+    // Register for notification when TopSites changes so that we can update
+    // ourself.
+    registrar_.Add(this, chrome::NOTIFICATION_TOP_SITES_CHANGED,
+                   content::Source<history::TopSites>(ts));
+  }
+
+  // We pre-emptively make a fetch for the available pages so we have the
+  // results sooner.
+  StartQueryForSuggested();
+
+  web_ui()->RegisterMessageCallback("getSuggested",
+      base::Bind(&SuggestedHandler::HandleGetSuggested,
+                 base::Unretained(this)));

[Dan Beam, 2012/02/09 01:43:06]

nit: no newline

[GeorgeY, 2012/02/10 00:00:36]

Done.

+
+  // Register ourselves for any suggested item blacklisting.
+  web_ui()->RegisterMessageCallback("blacklistURLFromSuggested",
+      base::Bind(&SuggestedHandler::HandleBlacklistURL,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback("removeURLsFromSuggestedBlacklist",
+      base::Bind(&SuggestedHandler::HandleRemoveURLsFromBlacklist,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback("clearSuggestedURLsBlacklist",
+      base::Bind(&SuggestedHandler::HandleClearBlacklist,
+                 base::Unretained(this)));
+}
+
+void SuggestedHandler::HandleGetSuggested(const ListValue* args) {
+  if (!NewTabUI::IsSuggestedPageEnabled())

[Dan Beam, 2012/02/09 01:43:06]

I don't think these preventative measures are necessary (as they seem like
they'd only be triggered by running chrome.send('getSuggested') from the webkit
console, in which case it's easier for the silly hacker to just close their
browser than to crash it via this means).  If anything, you should probably be
DCHECK()ing, IMO, but I'm not strongly opinionated on the matter.

[GeorgeY, 2012/02/10 00:00:36]

Yep, remnants of the bug when this function was always called - removed.

+    return;
+  if (!got_first_suggested_request_) {
+    // If our initial data is already here, return it.
+    SendPagesValue();
+    got_first_suggested_request_ = true;
+  } else {
+    StartQueryForSuggested();
+  }
+}
+
+void SuggestedHandler::SendPagesValue() {
+  if (pages_value_.get()) {
+    // TODO(georgey) add actual blacklist.
+    bool has_blacklisted_urls = false;
+    base::FundamentalValue has_blacklisted_urls_value(has_blacklisted_urls);
+    web_ui()->CallJavascriptFunction("setSuggestedPages",
+                                     *(pages_value_.get()),

[Dan Beam, 2012/02/09 01:43:06]

nit: can't one just use pages_value_.release()?

[GeorgeY, 2012/02/10 00:00:36]

Nope, you get memory leak.

+                                     has_blacklisted_urls_value);
+    pages_value_.reset();
+  }
+}
+
+void SuggestedHandler::StartQueryForSuggested() {
+  // TODO(georgey) change it to provide our data.
+  history::TopSites* ts = Profile::FromWebUI(web_ui())->GetTopSites();
+  if (ts) {

[Dan Beam, 2012/02/09 01:43:06]

when is this NULL?

[GeorgeY, 2012/02/10 00:00:36]

AFAIK, for TestProfileImpl

+    ts->GetMostVisitedURLs(
+        &topsites_consumer_,
+        base::Bind(&SuggestedHandler::OnSuggestedURLsAvailable,
+                   base::Unretained(this)));
+  }
+}
+
+void SuggestedHandler::HandleBlacklistURL(const ListValue* args) {
+  if (!NewTabUI::IsSuggestedPageEnabled())
+    return;
+  std::string url = UTF16ToUTF8(ExtractStringValue(args));
+  BlacklistURL(GURL(url));
+}
+
+void SuggestedHandler::HandleRemoveURLsFromBlacklist(const ListValue* args) {
+  if (!NewTabUI::IsSuggestedPageEnabled())
+    return;
+  DCHECK(args->GetSize() != 0);

[Dan Beam, 2012/02/09 01:43:06]

nit: > 0 (I understand this is a size_t, but say someday we change ListValue to
have a size of -1 if it hasn't been initialized or something...)

[GeorgeY, 2012/02/10 00:00:36]

Done.

+  // TODO(georgey) remove URLs from blacklist.
+}
+
+void SuggestedHandler::HandleClearBlacklist(const ListValue* args) {
+  if (!NewTabUI::IsSuggestedPageEnabled())
+    return;
+  // TODO(georgey) clear blacklist.

[Dan Beam, 2012/02/09 01:43:06]

I'd prefer you just wait until the TODO() is done before adding this method (no
need to make many devs and bots compile it in the mean time or possible leave it
around as crufty code later).

[GeorgeY, 2012/02/10 00:00:36]

We *do* want to add it before the first internal release.

+}
+
+void SuggestedHandler::SetPagesValueFromTopSites(
+    const history::MostVisitedURLList& data) {
+  // TODO(georgey) - change to our suggested pages - right now as a test
+  // returns top 20 sites in reverse order.
+  pages_value_.reset(new ListValue);

[Dan Beam, 2012/02/09 01:43:06]

Don't know what the style guide says about optional () for default constructors,
but I'd put them as you're doing this in JavaScript (as does everywhere else in
the file).

[GeorgeY, 2012/02/10 00:00:36]

Done.

+  for (size_t i = 0; i < data.size(); i++) {
+    const history::MostVisitedURL& url = data[data.size() - i - 1];

[Dan Beam, 2012/02/09 01:43:06]

nit: name this something different so it doesn't look like you accidentally
copy/pasta'd url.url. below, IMO

[GeorgeY, 2012/02/10 00:00:36]

Done.

+    DictionaryValue* page_value = new DictionaryValue();
+    if (url.url.is_empty()) {
+      page_value->SetBoolean("filler", true);
+      pages_value_->Append(page_value);
+      continue;
+    }
+
+    NewTabUI::SetURLTitleAndDirection(page_value,
+                                      url.title,
+                                      url.url);
+    pages_value_->Append(page_value);
+  }
+}
+
+void SuggestedHandler::OnSuggestedURLsAvailable(
+    const history::MostVisitedURLList& data) {
+  SetPagesValueFromTopSites(data);
+  if (got_first_suggested_request_)
+    SendPagesValue();
+}
+
+void SuggestedHandler::Observe(int type,
+                                 const content::NotificationSource& source,
+                                 const content::NotificationDetails& details) {
+  DCHECK_EQ(type, chrome::NOTIFICATION_TOP_SITES_CHANGED);
+
+  // Most visited urls changed, query again.
+  StartQueryForSuggested();
+}
+
+void SuggestedHandler::BlacklistURL(const GURL& url) {
+  // TODO(georgey) blacklist an URL.

[Dan Beam, 2012/02/09 01:43:06]

same for these two stubs

[GeorgeY, 2012/02/10 00:00:36]

see above

+}
+
+std::string SuggestedHandler::GetDictionaryKeyForURL(const std::string& url) {
+  return base::MD5String(url);
+}
+
+// static
+void SuggestedHandler::RegisterUserPrefs(PrefService* prefs) {
+  // TODO(georgey) add user preferences (such as own blacklist) as needed.
+}