Use heuristic to work out when to prompt for app install banners.

chrome/browser/android/banners/app_banner_manager.cc

 // Copyright 2014 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/android/banners/app_banner_manager.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 50 matching lines @@
 
 void AppBannerManager::BlockBanner(JNIEnv* env,
                                    jobject obj,
                                    jstring jurl,
                                    jstring jpackage) {
   if (!web_contents())
     return;
 
   GURL url(ConvertJavaStringToUTF8(env, jurl));
   std::string package_name = ConvertJavaStringToUTF8(env, jpackage);
-  AppBannerSettingsHelper::Block(web_contents(), url, package_name);
+  AppBannerSettingsHelper::RecordBannerEvent(
+      web_contents(), url, package_name,
+      AppBannerSettingsHelper::APP_BANNER_EVENT_DID_BLOCK, base::Time::Now());
 }
 
 void AppBannerManager::Block() const {
   if (!web_contents() || manifest_.IsEmpty())
     return;
 
-  AppBannerSettingsHelper::Block(web_contents(),
-                                 web_contents()->GetURL(),
-                                 manifest_.start_url.spec());
+  AppBannerSettingsHelper::RecordBannerEvent(
+      web_contents(), web_contents()->GetURL(), manifest_.start_url.spec(),
+      AppBannerSettingsHelper::APP_BANNER_EVENT_DID_BLOCK, base::Time::Now());
 }
 
 void AppBannerManager::Install() const {
   if (!web_contents())
     return;
 
   if (!manifest_.IsEmpty()) {
+    AppBannerSettingsHelper::RecordBannerEvent(
+        web_contents(), web_contents()->GetURL(), manifest_.start_url.spec(),
+        AppBannerSettingsHelper::APP_BANNER_EVENT_DID_ADD_TO_HOMESCREEN,
+        base::Time::Now());
+
     InstallManifestApp(manifest_, *app_icon_.get());
   }
 }
 
 gfx::Image AppBannerManager::GetIcon() const {
   return gfx::Image::CreateFrom1xBitmap(*app_icon_.get());
 }
 
 void AppBannerManager::ReplaceWebContents(JNIEnv* env,
                                           jobject obj,
@@ skipping 66 matching lines @@
 
 void AppBannerManager::OnDidCheckHasServiceWorker(bool has_same) {
   if (has_same) {
     // TODO(benwells): Check triggering parameters.
     GURL icon_url = ManifestIconSelector::FindBestMatchingIcon(
         manifest_.icons, GetPreferredIconSize(),
         gfx::Screen::GetScreenFor(web_contents()->GetNativeView()));
     if (icon_url.is_empty())
       return;
 
+    if (!CheckIfShouldShow(manifest_.start_url.spec()))
+      return;
+
     FetchIcon(icon_url);
   }
 }
 
+bool AppBannerManager::CheckIfShouldShow(
+    const std::string& package_or_start_url) {
+  AppBannerSettingsHelper::RecordBannerEvent(
+      web_contents(), validated_url_, package_or_start_url,
+      AppBannerSettingsHelper::APP_BANNER_EVENT_COULD_SHOW, base::Time::Now());
+  if (!AppBannerSettingsHelper::ShouldShowBanner(web_contents(), validated_url_,
+                                                 package_or_start_url,
+                                                 base::Time::Now())) {
+    return false;
+  }
+
+  AppBannerSettingsHelper::RecordBannerEvent(
+      web_contents(), validated_url_, package_or_start_url,
+      AppBannerSettingsHelper::APP_BANNER_EVENT_DID_SHOW, base::Time::Now());

[gone, 2015/02/05 22:21:10]

Seems strange to record that we did show it in a function called
CheckIfShouldShow().  ShowIfPossible()?

[benwells, 2015/02/06 16:36:28]

Good point. I've split this into two functions: RecordCouldShowBanner and
CheckIfShouldShow.

+  return true;
+}
+
 bool AppBannerManager::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(AppBannerManager, message)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_DidRetrieveMetaTagContent,
                         OnDidRetrieveMetaTagContent)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
@@ skipping 40 matching lines @@
     const std::string& tag_content,
     const GURL& expected_url) {
   DCHECK(web_contents());
   if (!success || tag_name != kBannerTag || validated_url_ != expected_url ||
       tag_content.size() >= chrome::kMaxMetaTagAttributeLength) {
     return;
   }
 
   banners::TrackDisplayEvent(DISPLAY_BANNER_REQUESTED);
 
-  if (!AppBannerSettingsHelper::IsAllowed(web_contents(),
-                                          expected_url,
-                                          tag_content)) {
+  if (!CheckIfShouldShow(tag_content))
     return;
-  }
 
   // Send the info to the Java side to get info about the app.
   JNIEnv* env = base::android::AttachCurrentThread();
   ScopedJavaLocalRef<jobject> jobj = weak_java_banner_view_manager_.get(env);
   if (jobj.is_null())
     return;
 
   ScopedJavaLocalRef<jstring> jurl(
       ConvertUTF8ToJavaString(env, expected_url.spec()));
   ScopedJavaLocalRef<jstring> jpackage(
@@ skipping 67 matching lines @@
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableAppInstallAlerts);
 }
 
 // Register native methods
 bool RegisterAppBannerManager(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace banners