Use DownloadManager to download non-html res when download icon pressed

We check the content's MIME type. If it is not meant for HTML page,we
route to DownloadManager.

BUG=673635

Review-Url: https://codereview.chromium.org/2841823004
Cr-Commit-Position: refs/heads/master@{#467931}

chrome/browser/android/offline_pages/downloads/offline_page_download_bridge.cc

@@ -28,6 +28,9 @@
 #include "components/offline_pages/core/offline_page_feature.h"
 #include "components/offline_pages/core/offline_page_model.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/download_manager.h"
+#include "content/public/browser/download_url_parameters.h"
+#include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/web_contents.h"
 #include "jni/OfflinePageDownloadBridge_jni.h"
 #include "net/base/filename_util.h"
@@ -337,10 +340,37 @@ void OfflinePageDownloadBridge::StartDownload(
     return;
 
   GURL url = web_contents->GetLastCommittedURL();
+  if (url.is_empty())
+    return;
+
   GURL original_url =
       offline_pages::OfflinePageUtils::GetOriginalURLFromWebContents(
           web_contents);
 
+  // If the page is not a HTML page, route to DownloadManager.
+  if (!offline_pages::OfflinePageUtils::CanDownloadAsOfflinePage(
+          url, web_contents->GetContentsMimeType())) {
+    content::DownloadManager* dlm = content::BrowserContext::GetDownloadManager(
+        web_contents->GetBrowserContext());
+    std::unique_ptr<content::DownloadUrlParameters> dl_params(
+        content::DownloadUrlParameters::CreateForWebContentsMainFrame(
+            web_contents, url));
+
+    content::NavigationEntry* entry =
+        web_contents->GetController().GetLastCommittedEntry();
+    // |entry| should not be null since otherwise an empty URL is returned from
+    // calling GetLastCommittedURL and we should bail out earlier.
+    DCHECK(entry);
+    content::Referrer referrer =
+        content::Referrer::SanitizeForRequest(url, entry->GetReferrer());
+    dl_params->set_referrer(referrer);
+
+    dl_params->set_prefer_cache(true);
+    dl_params->set_prompt(false);
+    dlm->DownloadUrl(std::move(dl_params));
+    return;
+  }
+
   ScopedJavaGlobalRef<jobject> j_tab_ref(env, j_tab);
 
   OfflinePageUtils::CheckDuplicateDownloads(

chrome/browser/android/offline_pages/downloads/resource_throttle.cc

@@ -10,18 +10,8 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/browser/web_contents.h"
-#include "net/base/mime_util.h"
 
 namespace {
-// Check if the url and mime type of a download resource should trigger handoff
-// to OfflinePages backend for full page load and snapshot.
-bool CanDownloadAsOfflinePage(
-    const GURL& url, const std::string& contents_mime_type) {
-  return url.SchemeIsHTTPOrHTTPS() &&
-      (net::MatchesMimeType(contents_mime_type, "text/html") ||
-          net::MatchesMimeType(contents_mime_type, "application/xhtml+xml"));
-}
-
 void WillStartOfflineRequestOnUIThread(
     const GURL& url,
     const content::ResourceRequestInfo::WebContentsGetter& contents_getter) {
@@ -51,8 +41,8 @@ void ResourceThrottle::WillProcessResponse(bool* defer) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   std::string mime_type;
   request_->GetMimeType(&mime_type);
-
-  if (CanDownloadAsOfflinePage(request_->url(), mime_type)) {
+  if (offline_pages::OfflinePageUtils::CanDownloadAsOfflinePage(request_->url(),
+                                                                mime_type)) {
     const content::ResourceRequestInfo* info =
         content::ResourceRequestInfo::ForRequest(request_);
     if (!info)

chrome/browser/android/offline_pages/offline_page_utils.cc

@@ -29,6 +29,7 @@
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/web_contents.h"
+#include "net/base/mime_util.h"
 
 namespace offline_pages {
 namespace {
@@ -298,4 +299,13 @@ void OfflinePageUtils::ScheduleDownload(content::WebContents* web_contents,
   tab_helper->ScheduleDownloadHelper(web_contents, name_space, url, ui_action);
 }
 
+// static
+bool OfflinePageUtils::CanDownloadAsOfflinePage(
+    const GURL& url,
+    const std::string& contents_mime_type) {
+  return url.SchemeIsHTTPOrHTTPS() &&
+         (net::MatchesMimeType(contents_mime_type, "text/html") ||
+          net::MatchesMimeType(contents_mime_type, "application/xhtml+xml"));
+}
+
 }  // namespace offline_pages

chrome/browser/android/offline_pages/offline_page_utils.h

@@ -109,6 +109,11 @@ class OfflinePageUtils {
                                const std::string& name_space,
                                const GURL& url,
                                DownloadUIActionFlags ui_action);
+
+  // Determines if offline page download should be triggered based on MIME type
+  // of download resource.
+  static bool CanDownloadAsOfflinePage(const GURL& url,
+                                       const std::string& contents_mime_type);
 };
 
 }  // namespace offline_pages