Add a flag in WebAPK's proto when the Web App Manifest is no longer available.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
index 8aacf80f512fd19202852de68ff89a67204ab4a7..66b54fc0388295f64aba0cfce7f1c8894f3f6916 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
@@ -112,13 +112,13 @@ public class WebApkUpdateManager implements ManifestUpgradeDetector.Callback {
         recordUpdate(storage, false);
 
         if (info != null) {
-            updateAsync(info, bestIconUrl);
+            updateAsync(info, bestIconUrl, false);
             return;
         }
 
         // Since we could not fetch the Web Manifest, we do not know what the best icon URL is. Pass
         // an empty "best icon URL" to tell the server that there is no best icon URL.

[pkotwicz, 2016/12/09 22:18:55]

Please add a comment describing why we set the staleManifest flag.

Perhaps: "Tell the server that the our version of the Web Manifest might be
stale and to ignore our Web Manifest data if the server's Web Manifest data is
newer. This scenario can occur if the Web Manifest is temporarily unreachable."

Something I have not considered is what occurs when a Web Manifest transitions
from being "generic" to being "customized to each user". I don't think that it
is possible to upgrade a CertifiedWebAPK to a OneOffWebAPK. If a site
transitions from the certified case to the OneOff case I think that all of the
currently installed CertifiedWebAPKs will permanently fail to update.
Perhaps:
- the staleManifest flag should tell the server whether it should refetch the
Web Manifest
- the server should return the newest CertifiedWebApk it has if the fetched Web
Manifest data does not match what is provided by the client.

[Xi Han, 2016/12/13 20:59:15]

SGTM, added.
 
A certified WebAPK won't be upgraded to a OneOffWebAPK. That is why the server
will already keep a cached version of a certified WebAPK.

-        updateAsync(mInfo, "");
+        updateAsync(mInfo, "", true);
     }
 
     /**
@@ -131,14 +131,18 @@ public class WebApkUpdateManager implements ManifestUpgradeDetector.Callback {
     /**
      * Sends request to WebAPK Server to update WebAPK.
      */
-    protected void updateAsync(WebApkInfo info, String bestIconUrl) {
+    protected void updateAsync(WebApkInfo info, String bestIconUrl, boolean staleManifest) {
         int versionCode = readVersionCodeFromAndroidManifest(info.webApkPackageName());
-        String bestIconMurmur2Hash = info.iconUrlToMurmur2HashMap().get(bestIconUrl);
+        String[] iconUrls = info.iconUrlToMurmur2HashMap().keySet().toArray(new String[0]);
+        String[] iconHashes = new String[iconUrls.length];
+        for (int i = 0; i < iconUrls.length; ++i) {

[pkotwicz, 2016/12/09 22:18:55]

Nit: I suspect that Dominick will want you to use
iconUrlToMurmur2HashMap.entrySet() here

[Xi Han, 2016/12/13 20:59:15]

Done.

+            String iconHash = info.iconUrlToMurmur2HashMap().get(iconUrls[i]);
+            iconHashes[i] = iconHash != null ? iconHash : "";
+        }
         nativeUpdateAsync(info.id(), info.manifestStartUrl(), info.scopeUri().toString(),
-                info.name(), info.shortName(), bestIconUrl, bestIconMurmur2Hash, info.icon(),
-                info.iconUrlToMurmur2HashMap().keySet().toArray(new String[0]), info.displayMode(),
-                info.orientation(), info.themeColor(), info.backgroundColor(), info.manifestUrl(),
-                info.webApkPackageName(), versionCode);
+                info.name(), info.shortName(), bestIconUrl, info.icon(), iconUrls, iconHashes,
+                info.displayMode(), info.orientation(), info.themeColor(), info.backgroundColor(),
+                info.manifestUrl(), info.webApkPackageName(), versionCode, staleManifest);
     }
 
     /**
@@ -263,7 +267,8 @@ public class WebApkUpdateManager implements ManifestUpgradeDetector.Callback {
     }
 
     private static native void nativeUpdateAsync(String id, String startUrl, String scope,
-            String name, String shortName, String bestIconUrl, String bestIconMurmur2Hash,
-            Bitmap bestIcon, String[] iconUrls, int displayMode, int orientation, long themeColor,
-            long backgroundColor, String manifestUrl, String webApkPackage, int webApkVersion);
+            String name, String shortName, String bestIconUrl, Bitmap bestIcon, String[] iconUrls,
+            String[] iconHashes, int displayMode, int orientation, long themeColor,
+            long backgroundColor, String manifestUrl, String webApkPackage, int webApkVersion,
+            boolean staleManifest);
 }