Restructure SDCH layering to allow more separation (observer/1->[0,n]

net/base/sdch_manager.cc

Index: net/base/sdch_manager.cc
diff --git a/net/base/sdch_manager.cc b/net/base/sdch_manager.cc
index 0f31d5cee8ad84e4ea2acacd8c06a52b786847b2..f53fcf4e80fdddc97974ae8110dc13cd19d3060b 100644
--- a/net/base/sdch_manager.cc
+++ b/net/base/sdch_manager.cc
@@ -11,6 +11,7 @@
 #include "base/strings/string_util.h"
 #include "crypto/sha2.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "net/base/sdch_observer.h"
 #include "net/url_request/url_request_http_job.h"
 
 namespace {
@@ -257,14 +258,14 @@ SdchManager::~SdchManager() {
 void SdchManager::ClearData() {
   blacklisted_domains_.clear();
   allow_latency_experiment_.clear();
-  if (fetcher_.get())
-    fetcher_->Cancel();
 
   // Note that this may result in not having dictionaries we've advertised
   // for incoming responses.  The window is relatively small (as ClearData()
   // is not expected to be called frequently), so we rely on meta-refresh
   // to handle this case.
   dictionaries_.clear();
+
+  FOR_EACH_OBSERVER(SdchObserver, observers_, OnClearDictionaries(this));
 }
 
 // static
@@ -272,11 +273,6 @@ void SdchManager::SdchErrorRecovery(ProblemCodes problem) {
   UMA_HISTOGRAM_ENUMERATION("Sdch3.ProblemCodes_4", problem, MAX_PROBLEM_CODE);
 }
 
-void SdchManager::set_sdch_fetcher(scoped_ptr<SdchFetcher> fetcher) {
-  DCHECK(CalledOnValidThread());
-  fetcher_ = fetcher.Pass();
-}
-
 // static
 void SdchManager::EnableSdchSupport(bool enabled) {
   g_sdch_enabled_ = enabled;
@@ -377,13 +373,13 @@ bool SdchManager::IsInSupportedDomain(const GURL& url) {
   return false;
 }
 
-void SdchManager::FetchDictionary(const GURL& request_url,
+void SdchManager::OnGetDictionary(const GURL& request_url,
                                   const GURL& dictionary_url) {
-  DCHECK(CalledOnValidThread());
-  if (CanFetchDictionary(request_url, dictionary_url) && fetcher_.get()) {
-    ++fetches_count_for_testing_;
-    fetcher_->Schedule(dictionary_url);
-  }
+  if (!CanFetchDictionary(request_url, dictionary_url))
+    return;
+
+  FOR_EACH_OBSERVER(SdchObserver, observers_,
+                    OnGetDictionary(this, request_url, dictionary_url));
 }
 
 bool SdchManager::CanFetchDictionary(const GURL& referring_url,
@@ -499,6 +495,16 @@ void SdchManager::SetAllowLatencyExperiment(const GURL& url, bool enable) {
   allow_latency_experiment_.erase(it);
 }
 
+void SdchManager::AddObserver(SdchObserver* observer) {
+  observers_.AddObserver(observer);
+  observer->AddRef();
+}
+
+void SdchManager::RemoveObserver(SdchObserver* observer) {
+  observers_.RemoveObserver(observer);
+  observer->RemoveRef();
+}
+
 void SdchManager::AddSdchDictionary(const std::string& dictionary_text,
     const GURL& dictionary_url) {
   DCHECK(CalledOnValidThread());