🛃 Tidy up CustomTabActivitys Observers.

Split CustomTabActivity's PageLoadMetrics.Observers according to their
purpose. Also create the TabObserverRegistrar class that deals with
attaching these observers to Tabs as they enter and exit the TabModel.

Bug: none
Change-Id: Ic434ead9c5167eb876f91af33b54dfd3d50493cd
Reviewed-on: https://chromium-review.googlesource.com/1154968Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Commit-Queue: Peter Conn <peconn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580474}

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

+// Copyright 2018 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.customtabs;
+
+import org.chromium.chrome.browser.metrics.PageLoadMetrics;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.content_public.browser.WebContents;
+
+/**
+ * Notifies the provided {@link CustomTabObserver} when first meaningful paint occurs.
+ */
+/* package */ class FirstMeaningfulPaintObserver implements PageLoadMetrics.Observer {
+    private final Tab mTab;
+    private final CustomTabObserver mCustomTabObserver;
+
+    /* package */ FirstMeaningfulPaintObserver(CustomTabObserver tabObserver, Tab tab) {
+        mCustomTabObserver = tabObserver;
+        mTab = tab;
+    }
+
+    @Override
+    public void onFirstMeaningfulPaint(WebContents webContents, long navigationId,
+            long navigationStartTick, long firstContentfulPaintMs) {
+        if (webContents != mTab.getWebContents()) return;
+
+        mCustomTabObserver.onFirstMeaningfulPaint(mTab);
+    }
+}

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

+// Copyright 2018 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.customtabs;
+
+import android.os.Bundle;
+import android.support.customtabs.CustomTabsSessionToken;
+
+import org.chromium.chrome.browser.metrics.PageLoadMetrics;
+import org.chromium.chrome.browser.net.spdyproxy.DataReductionProxySettings;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.content_public.browser.WebContents;
+
+/**
+ * Notifies the provided {@link CustomTabsConnection} of page load metrics, such as time until first
+ * contentful paint.
+ */
+class PageLoadMetricsObserver implements PageLoadMetrics.Observer {
+    private final CustomTabsConnection mConnection;
+    private final CustomTabsSessionToken mSession;
+    private final Tab mTab;
+
+    /* package */ PageLoadMetricsObserver(CustomTabsConnection connection,
+            CustomTabsSessionToken session, Tab tab) {
+        mConnection = connection;
+        mSession = session;
+        mTab = tab;
+    }
+
+    @Override
+    public void onNetworkQualityEstimate(WebContents webContents, long navigationId,
+            int effectiveConnectionType, long httpRttMs, long transportRttMs) {
+        if (webContents != mTab.getWebContents()) return;
+
+        Bundle args = new Bundle();
+        args.putLong(PageLoadMetrics.EFFECTIVE_CONNECTION_TYPE, effectiveConnectionType);
+        args.putLong(PageLoadMetrics.HTTP_RTT, httpRttMs);
+        args.putLong(PageLoadMetrics.TRANSPORT_RTT, transportRttMs);
+        args.putBoolean(CustomTabsConnection.DATA_REDUCTION_ENABLED,
+                DataReductionProxySettings.getInstance().isDataReductionProxyEnabled());
+        mConnection.notifyPageLoadMetrics(mSession, args);
+    }
+
+    @Override
+    public void onFirstContentfulPaint(WebContents webContents, long navigationId,
+            long navigationStartTick, long firstContentfulPaintMs) {
+        if (webContents != mTab.getWebContents()) return;
+
+        mConnection.notifySinglePageLoadMetric(mSession, PageLoadMetrics.FIRST_CONTENTFUL_PAINT,
+                navigationStartTick, firstContentfulPaintMs);
+    }
+
+    @Override
+    public void onLoadEventStart(WebContents webContents, long navigationId,
+            long navigationStartTick, long loadEventStartMs) {
+        if (webContents != mTab.getWebContents()) return;
+
+        mConnection.notifySinglePageLoadMetric(mSession, PageLoadMetrics.LOAD_EVENT_START,
+                navigationStartTick, loadEventStartMs);
+    }
+
+    @Override
+    public void onLoadedMainResource(WebContents webContents, long navigationId,
+            long dnsStartMs, long dnsEndMs, long connectStartMs, long connectEndMs,
+            long requestStartMs, long sendStartMs, long sendEndMs) {
+        if (webContents != mTab.getWebContents()) return;
+
+        Bundle args = new Bundle();
+        args.putLong(PageLoadMetrics.DOMAIN_LOOKUP_START, dnsStartMs);
+        args.putLong(PageLoadMetrics.DOMAIN_LOOKUP_END, dnsEndMs);
+        args.putLong(PageLoadMetrics.CONNECT_START, connectStartMs);
+        args.putLong(PageLoadMetrics.CONNECT_END, connectEndMs);
+        args.putLong(PageLoadMetrics.REQUEST_START, requestStartMs);
+        args.putLong(PageLoadMetrics.SEND_START, sendStartMs);
+        args.putLong(PageLoadMetrics.SEND_END, sendEndMs);
+        mConnection.notifyPageLoadMetrics(mSession, args);
+    }
+}

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

+// Copyright 2018 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.customtabs;
+
+import org.chromium.chrome.browser.metrics.PageLoadMetrics;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tab.TabObserver;
+import org.chromium.chrome.browser.tabmodel.EmptyTabModelObserver;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Adds and removes the given {@link PageLoadMetrics.Observer}s and {@link TabObserver}s to Tabs as
+ * they enter/leave the TabModel.
+ *
+ * // TODO(peconn): Get rid of EmptyTabModelObserver now that we have Java 8 default methods.
+ */
+public class TabObserverRegistrar extends EmptyTabModelObserver {
+    private final Set<PageLoadMetrics.Observer> mPageLoadMetricsObservers = new HashSet<>();
+    private final Set<TabObserver> mTabObservers = new HashSet<>();
+
+    /**
+     * Registers a {@link PageLoadMetrics.Observer} to be managed by this Registrar.
+     */
+    public void registerPageLoadMetricsObserver(PageLoadMetrics.Observer observer) {
+        mPageLoadMetricsObservers.add(observer);
+    }
+
+    /**
+     * Registers a {@link TabObserver} to be managed by this Registrar.
+     */
+    public void registerTabObserver(TabObserver observer) {
+        mTabObservers.add(observer);
+    }
+
+    @Override
+    public void didAddTab(Tab tab, int type) {
+        addObserversForTab(tab);
+    }
+
+    @Override
+    public void didCloseTab(int tabId, boolean incognito) {
+        // We don't need to remove the Tab Observers since it's closed.
+        // TODO(peconn): Do we really want to remove the *global* PageLoadMetrics observers here?
+        removePageLoadMetricsObservers();
+    }
+
+    @Override
+    public void tabRemoved(Tab tab) {
+        removePageLoadMetricsObservers();
+        removeTabObservers(tab);
+    }
+
+    /**
+     * Adds all currently registered {@link PageLoadMetrics.Observer}s and {@link TabObserver}s to
+     * the global {@link PageLoadMetrics} object and the given {@link Tab} respectively.
+     */
+    public void addObserversForTab(Tab tab) {
+        addPageLoadMetricsObservers();
+        addTabObservers(tab);
+    }
+
+    private void addPageLoadMetricsObservers() {
+        for (PageLoadMetrics.Observer observer : mPageLoadMetricsObservers) {
+            PageLoadMetrics.addObserver(observer);
+        }
+    }
+
+    private void removePageLoadMetricsObservers() {
+        for (PageLoadMetrics.Observer observer : mPageLoadMetricsObservers) {
+            PageLoadMetrics.removeObserver(observer);
+        }
+    }
+
+    private void addTabObservers(Tab tab) {
+        for (TabObserver observer : mTabObservers) {
+            tab.addObserver(observer);
+        }
+    }
+
+    private void removeTabObservers(Tab tab) {
+        for (TabObserver observer : mTabObservers) {
+            tab.removeObserver(observer);
+        }
+    }
+}

chrome/android/java_sources.gni

@@ -365,10 +365,12 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java",
   "java/src/org/chromium/chrome/browser/customtabs/CustomTabNavigationEventObserver.java",
   "java/src/org/chromium/chrome/browser/customtabs/CustomTabObserver.java",
+  "java/src/org/chromium/chrome/browser/customtabs/CustomTabTabPersistencePolicy.java",
   "java/src/org/chromium/chrome/browser/customtabs/CustomTabsConnection.java",
   "java/src/org/chromium/chrome/browser/customtabs/CustomTabsConnectionService.java",
-  "java/src/org/chromium/chrome/browser/customtabs/CustomTabTabPersistencePolicy.java",
+  "java/src/org/chromium/chrome/browser/customtabs/FirstMeaningfulPaintObserver.java",
   "java/src/org/chromium/chrome/browser/customtabs/NavigationInfoCaptureTrigger.java",
+  "java/src/org/chromium/chrome/browser/customtabs/PageLoadMetricsObserver.java",
   "java/src/org/chromium/chrome/browser/customtabs/RequestThrottler.java",
   "java/src/org/chromium/chrome/browser/customtabs/SeparateTaskCustomTabActivity.java",
   "java/src/org/chromium/chrome/browser/customtabs/SeparateTaskCustomTabActivity0.java",
@@ -382,6 +384,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/customtabs/SeparateTaskCustomTabActivity8.java",
   "java/src/org/chromium/chrome/browser/customtabs/SeparateTaskCustomTabActivity9.java",
   "java/src/org/chromium/chrome/browser/customtabs/SeparateTaskManagedCustomTabActivity.java",
+  "java/src/org/chromium/chrome/browser/customtabs/TabObserverRegistrar.java",
   "java/src/org/chromium/chrome/browser/customtabs/dynamicmodule/ActivityDelegate.java",
   "java/src/org/chromium/chrome/browser/customtabs/dynamicmodule/ActivityHostImpl.java",
   "java/src/org/chromium/chrome/browser/customtabs/dynamicmodule/ModuleEntryPoint.java",