Simplify BrowserContext by removing redundant methods.

components/precache/content/precache_manager.cc

Index: components/precache/content/precache_manager.cc
diff --git a/components/precache/content/precache_manager.cc b/components/precache/content/precache_manager.cc
index a815b16f583bcbe7f2ff7e438dca47a6b9294a20..1d2ddb653b7742cb2d7257d3ea1aeaa37f5aba25 100644
--- a/components/precache/content/precache_manager.cc
+++ b/components/precache/content/precache_manager.cc
@@ -23,6 +23,7 @@
 #include "components/variations/variations_associated_data.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/storage_partition.h"
 #include "net/base/network_change_notifier.h"
 
 using content::BrowserThread;
@@ -279,13 +280,15 @@ void PrecacheManager::OnHostsReceived(
     hosts.push_back(host_count.first);
 
   // Start precaching.
-  precache_fetcher_.reset(
-      new PrecacheFetcher(hosts, browser_context_->GetRequestContext(),
-                          GURL(variations::GetVariationParamValue(
-                              kPrecacheFieldTrialName, kConfigURLParam)),
-                          variations::GetVariationParamValue(
-                              kPrecacheFieldTrialName, kManifestURLPrefixParam),
-                          this));
+  precache_fetcher_.reset(new PrecacheFetcher(
+      hosts,
+      content::BrowserContext::GetDefaultStoragePartition(browser_context_)->
+            GetURLRequestContext(),
+      GURL(variations::GetVariationParamValue(
+          kPrecacheFieldTrialName, kConfigURLParam)),
+      variations::GetVariationParamValue(
+          kPrecacheFieldTrialName, kManifestURLPrefixParam),
+      this));
   precache_fetcher_->Start();
 }