[NTP] Implement reactions to snippet context menu actions.

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java
index 7a8158252ab8c24cea0daaa4fc29f69667e85858..da10c9b97b504c3236baca4c5df76e0506bb707d 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java
@@ -354,21 +354,15 @@ public class NewTabPage
             mSnippetsBridge.onSuggestionOpened(article, windowOpenDisposition);
             NewTabPageUma.recordAction(NewTabPageUma.ACTION_OPENED_SNIPPET);
 
-            if (article.isDownload() && article.mIsDownloadedAsset) {
+            if (article.mIsDownloadedAsset) {
+                assert windowOpenDisposition == WindowOpenDisposition.CURRENT_TAB
+                        || windowOpenDisposition == WindowOpenDisposition.NEW_WINDOW
+                        || windowOpenDisposition == WindowOpenDisposition.NEW_FOREGROUND_TAB;
                 DownloadUtils.openFile(
                         article.getDownloadAssetFile(), article.getDownloadAssetMimeType(), false);
                 return;
             }
 
-            if (article.getOfflinePageOfflineId() != null) {
-                // TODO(vitaliii): Handle other window dispositions.
-                if (windowOpenDisposition == WindowOpenDisposition.CURRENT_TAB) {
-                    OfflinePageUtils.openInExistingTab(
-                            article.mUrl, article.getOfflinePageOfflineId(), mTab);
-                }
-                return;
-            }
-
             if (article.isRecentTab()) {
                 assert windowOpenDisposition == WindowOpenDisposition.CURRENT_TAB;
                 // TODO(vitaliii): Add a debug check that the result is true after crbug.com/662924
@@ -382,8 +376,18 @@ public class NewTabPage
                 NewTabPageUma.monitorContentSuggestionVisit(mTab, article.mCategory);
             }
 
-            LoadUrlParams loadUrlParams =
-                    new LoadUrlParams(article.mUrl, PageTransition.AUTO_BOOKMARK);
+            LoadUrlParams loadUrlParams;
+            // The snippet's offline page is ignored if the snippet is saved or opened in incognito.
+            if (article.getOfflinePageOfflineId() != null
+                    && windowOpenDisposition != WindowOpenDisposition.SAVE_TO_DISK
+                    && windowOpenDisposition != WindowOpenDisposition.OFF_THE_RECORD) {
+                loadUrlParams = OfflinePageUtils.getLoadUrlParamsForOpeningOfflineVersion(
+                        article.mUrl, article.getOfflinePageOfflineId());
+                // Extra headers are not read in loadUrl, but verbatim headers are.
+                loadUrlParams.setVerbatimHeaders(loadUrlParams.getExtraHeadersString());
+            } else {
+                loadUrlParams = new LoadUrlParams(article.mUrl, PageTransition.AUTO_BOOKMARK);
+            }
 
             // For article suggestions, we set the referrer. This is exploited
             // to filter out these history entries for NTP tiles.
@@ -402,8 +406,6 @@ public class NewTabPage
             int tabIndex = TabModelUtils.getTabIndexById(tabModel, tabId);
             if (tabIndex == TabModel.INVALID_TAB_INDEX) return false;
             TabModelUtils.setIndex(tabModel, tabIndex);
-            assert recentTabArticle.getOfflinePageOfflineId().equals(
-                    Long.parseLong(recentTabArticle.getRecentTabId()));
             OfflinePageUtils.openInExistingTab(recentTabArticle.mUrl,
                     recentTabArticle.getOfflinePageOfflineId(), tabModel.getTabAt(tabIndex));
             return true;