Add support for showing CSS with distilled articles.

components/dom_distiller/content/dom_distiller_viewer_source.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 "components/dom_distiller/content/dom_distiller_viewer_source.h"
 
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "components/dom_distiller/core/dom_distiller_service.h"
 #include "components/dom_distiller/core/proto/distilled_page.pb.h"
 #include "components/dom_distiller/core/task_tracker.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "grit/component_strings.h"
 #include "grit/dom_distiller_resources.h"
 #include "net/base/escape.h"
 #include "net/url_request/url_request.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "url/gurl.h"
 
 namespace {
 
+const char kCssPath[] = "readability.css";
+
 std::string ReplaceHtmlTemplateValues(std::string title, std::string content) {
   base::StringPiece html_template =
       ResourceBundle::GetSharedInstance().GetRawDataResource(
           IDR_DOM_DISTILLER_VIEWER_HTML);
   std::vector<std::string> substitutions;
-  substitutions.push_back(title);    // $1
-  substitutions.push_back(title);    // $2
-  substitutions.push_back(content);  // $3
+  substitutions.push_back(title);     // $1
+  substitutions.push_back(kCssPath);  // $2
+  substitutions.push_back(title);     // $3
+  substitutions.push_back(content);   // $4
   return ReplaceStringPlaceholders(html_template, substitutions, NULL);
 }
 
 }  // namespace
 
 namespace dom_distiller {
 
 // Handles receiving data asynchronously for a specific entry, and passing
 // it along to the data callback for the data source.
 class RequestViewerHandle : public ViewRequestDelegate {
@@ skipping 60 matching lines @@
     int render_frame_id,
     const content::URLDataSource::GotDataCallback& callback) {
   content::RenderFrameHost* render_frame_host =
       content::RenderFrameHost::FromID(render_process_id, render_frame_id);
   DCHECK(render_frame_host);
   content::RenderViewHost* render_view_host =
       render_frame_host->GetRenderViewHost();
   DCHECK(render_view_host);
   CHECK_EQ(0, render_view_host->GetEnabledBindings());
 
+  if (kCssPath == path) {
+    std::string css = ResourceBundle::GetSharedInstance()
+                          .GetRawDataResource(IDR_DISTILLER_CSS)
+                          .as_string();
+    callback.Run(base::RefCountedString::TakeString(&css));
+    return;
+  }
+
   RequestViewerHandle* request_viewer_handle =
       new RequestViewerHandle(callback);
   std::string entry_id = StringToUpperASCII(path);
   scoped_ptr<ViewerHandle> viewer_handle =
       dom_distiller_service_->ViewEntry(request_viewer_handle, entry_id);
   if (viewer_handle) {
     // The service returned a |ViewerHandle| and guarantees it will call
     // the |RequestViewerHandle|, so passing ownership to it, to ensure the
     // request is not cancelled. The |RequestViewerHandle| will delete itself
     // after receiving the callback.
     request_viewer_handle->TakeViewerHandle(viewer_handle.Pass());
   } else {
     // The service did not return a |ViewerHandle|, which means the
     // |RequestViewerHandle| will never be called, so clean up now.
     delete request_viewer_handle;
 
     std::string title = l10n_util::GetStringUTF8(
         IDS_DOM_DISTILLER_VIEWER_FAILED_TO_FIND_ARTICLE_TITLE);
     std::string content = l10n_util::GetStringUTF8(
         IDS_DOM_DISTILLER_VIEWER_FAILED_TO_FIND_ARTICLE_CONTENT);
     std::string html = ReplaceHtmlTemplateValues(title, content);
     callback.Run(base::RefCountedString::TakeString(&html));
   }
 };
 
 std::string DomDistillerViewerSource::GetMimeType(const std::string& path)
     const {
+  if (path == kCssPath)
+    return "text/css";
   return "text/html";
 }
 
 bool DomDistillerViewerSource::ShouldServiceRequest(
     const net::URLRequest* request) const {
   return request->url().SchemeIs(scheme_.c_str());
 }
 
 void DomDistillerViewerSource::WillServiceRequest(
     const net::URLRequest* request,
     std::string* path) const {
-  // Since the full request is not available to StartDataRequest, replace the
-  // path to contain the data needed.
-  *path = request->url().host();
+  if (*path != kCssPath) {
+    // Since the full request is not available to StartDataRequest, replace the
+    // path to contain the data needed.
+    *path = request->url().host();
+  }
 };
 
+std::string DomDistillerViewerSource::GetContentSecurityPolicyObjectSrc()
+    const {
+  return "object-src 'none'; style-src 'self'";
+}
+
 }  // namespace dom_distiller