NTP: Prevent tab sync icons from being cached.

BUG=127463
TEST=Manual.

Review URL: https://chromiumcodereview.appspot.com/10407066

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@138112 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/webui/chrome_url_data_manager.h

@@ -107,6 +107,9 @@ class ChromeURLDataManager : public ProfileKeyedService {
     // TODO: nuke this and convert all callers to not replace.
     virtual bool ShouldReplaceExistingSource() const;
 
+    // Returns true if responses from this DataSource can be cached.
+    virtual bool AllowCaching() const { return true; }
+
     static void SetFontAndTextDirection(
         base::DictionaryValue* localized_strings);
 

chrome/browser/ui/webui/chrome_url_data_manager_backend.cc

@@ -177,10 +177,14 @@ class URLRequestChromeJob : public net::URLRequestJob {
   // for us.
   void DataAvailable(base::RefCountedMemory* bytes);
 
-  void SetMimeType(const std::string& mime_type) {
+  void set_mime_type(const std::string& mime_type) {
     mime_type_ = mime_type;
   }
 
+  void set_allow_caching(bool allow_caching) {
+    allow_caching_ = allow_caching;
+  }
+
  private:
   virtual ~URLRequestChromeJob();
 
@@ -204,6 +208,9 @@ class URLRequestChromeJob : public net::URLRequestJob {
   int pending_buf_size_;
   std::string mime_type_;
 
+  // If true, set a header in the response to prevent it from being cached.
+  bool allow_caching_;
+
   // The backend is owned by ChromeURLRequestContext and always outlives us.
   ChromeURLDataManagerBackend* backend_;
 
@@ -217,6 +224,7 @@ URLRequestChromeJob::URLRequestChromeJob(net::URLRequest* request,
     : net::URLRequestJob(request),
       data_offset_(0),
       pending_buf_size_(0),
+      allow_caching_(true),
       backend_(backend),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
   DCHECK(backend);
@@ -254,6 +262,8 @@ void URLRequestChromeJob::GetResponseInfo(net::HttpResponseInfo* info) {
   // indistiguishable from other error types. Instant relies on getting a 200.
   info->headers = new net::HttpResponseHeaders("HTTP/1.1 200 OK");
   AddContentSecurityPolicyHeader(request_->url(), info->headers);
+  if (!allow_caching_)
+    info->headers->AddHeader("Cache-Control: no-cache");
 }
 
 void URLRequestChromeJob::DataAvailable(base::RefCountedMemory* bytes) {
@@ -417,7 +427,8 @@ bool ChromeURLDataManagerBackend::StartRequest(const GURL& url,
   // TODO(eroman): would be nicer if the mimetype were set at the same time
   // as the data blob. For now do it here, since NotifyHeadersComplete() is
   // going to get called once we return.
-  job->SetMimeType(source->GetMimeType(path));
+  job->set_mime_type(source->GetMimeType(path));
+  job->set_allow_caching(source->AllowCaching());
 
   const ChromeURLRequestContext* context =
       static_cast<const ChromeURLRequestContext*>(job->request()->context());

chrome/browser/ui/webui/session_favicon_source.cc

@@ -49,3 +49,9 @@ bool SessionFaviconSource::ShouldReplaceExistingSource() const {
   // requests on the floor.
   return false;
 }
+
+bool SessionFaviconSource::AllowCaching() const {
+  // Prevent responses from being cached, otherwise session favicons won't
+  // update in a timely manner.
+  return false;
+}

chrome/browser/ui/webui/session_favicon_source.h

@@ -19,15 +19,13 @@ class SessionFaviconSource : public FaviconSource {
  public:
   explicit SessionFaviconSource(Profile* profile);
 
-  // Called when the network layer has requested a resource underneath
-  // the path we registered.
+  // FaviconSource implementation.
   virtual void StartDataRequest(const std::string& path,
                                 bool is_incognito,
                                 int request_id) OVERRIDE;
-
   virtual std::string GetMimeType(const std::string&) const OVERRIDE;
-
   virtual bool ShouldReplaceExistingSource() const OVERRIDE;
+  virtual bool AllowCaching() const OVERRIDE;
 
  protected:
   virtual ~SessionFaviconSource();