Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

components/browsing_data/storage_partition_http_cache_data_remover.cc

Index: components/browsing_data/storage_partition_http_cache_data_remover.cc
diff --git a/components/browsing_data/storage_partition_http_cache_data_remover.cc b/components/browsing_data/storage_partition_http_cache_data_remover.cc
index c53c0be6409300347be7e76bc47cb98a9f1d1032..f8519fe3a8a1fccadc21836798e43d15006be7b1 100644
--- a/components/browsing_data/storage_partition_http_cache_data_remover.cc
+++ b/components/browsing_data/storage_partition_http_cache_data_remover.cc
@@ -7,7 +7,10 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/storage_partition.h"
 #include "net/base/sdch_manager.h"
+#include "net/disk_cache/blockfile/backend_impl.h"
 #include "net/disk_cache/disk_cache.h"
+#include "net/disk_cache/memory/mem_backend_impl.h"
+#include "net/disk_cache/simple/simple_backend_impl.h"
 #include "net/http/http_cache.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
@@ -26,7 +29,9 @@ StoragePartitionHttpCacheDataRemover::StoragePartitionHttpCacheDataRemover(
       main_context_getter_(main_context_getter),
       media_context_getter_(media_context_getter),
       next_cache_state_(STATE_NONE),
-      cache_(nullptr) {
+      cache_(nullptr),
+      count_only_(false),
+      calculation_result_(0) {
 }
 
 StoragePartitionHttpCacheDataRemover::~StoragePartitionHttpCacheDataRemover() {
@@ -48,6 +53,22 @@ void StoragePartitionHttpCacheDataRemover::Remove(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!done_callback.is_null());
   done_callback_ = done_callback;
+  count_only_ = false;
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(
+          &StoragePartitionHttpCacheDataRemover::ClearHttpCacheOnIOThread,
+          base::Unretained(this)));
+}
+
+void StoragePartitionHttpCacheDataRemover::Count(
+    const net::Int64CompletionCallback& result_callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(!result_callback.is_null());
+  result_callback_ = result_callback;
+  calculation_result_ = 0;
+  count_only_ = true;
 
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
@@ -69,7 +90,10 @@ void StoragePartitionHttpCacheDataRemover::ClearHttpCacheOnIOThread() {
 
 void StoragePartitionHttpCacheDataRemover::ClearedHttpCache() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  done_callback_.Run();
+  if (count_only_)
+    result_callback_.Run(calculation_result_);
+  else
+    done_callback_.Run();
   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
 
@@ -96,19 +120,21 @@ void StoragePartitionHttpCacheDataRemover::DoClearCache(int rv) {
                                 ? STATE_DELETE_MAIN
                                 : STATE_DELETE_MEDIA;
 
-        // Clear QUIC server information from memory and the disk cache.
-        http_cache->GetSession()
-            ->quic_stream_factory()
-            ->ClearCachedStatesInCryptoConfig();
-
-        // Clear SDCH dictionary state.
-        net::SdchManager* sdch_manager =
-            getter->GetURLRequestContext()->sdch_manager();
-        // The test is probably overkill, since chrome should always have an
-        // SdchManager.  But in general the URLRequestContext  is *not*
-        // guaranteed to have an SdchManager, so checking is wise.
-        if (sdch_manager)
-          sdch_manager->ClearData();
+        if (!count_only_) {
+          // Clear QUIC server information from memory and the disk cache.
+          http_cache->GetSession()
+              ->quic_stream_factory()
+              ->ClearCachedStatesInCryptoConfig();
+
+          // Clear SDCH dictionary state.
+          net::SdchManager* sdch_manager =
+              getter->GetURLRequestContext()->sdch_manager();
+          // The test is probably overkill, since chrome should always have an
+          // SdchManager.  But in general the URLRequestContext  is *not*
+          // guaranteed to have an SdchManager, so checking is wise.
+          if (sdch_manager)
+            sdch_manager->ClearData();
+        }
 
         rv = http_cache->GetBackend(
             &cache_,
@@ -125,14 +151,34 @@ void StoragePartitionHttpCacheDataRemover::DoClearCache(int rv) {
         // |cache_| can be null if it cannot be initialized.
         if (cache_) {
           if (delete_begin_.is_null()) {
-            rv = cache_->DoomAllEntries(
-                base::Bind(&StoragePartitionHttpCacheDataRemover::DoClearCache,
-                           base::Unretained(this)));
+            if (count_only_) {
+              // TODO(msramek): Implement analogous |CalculateSizeOfAllEntries|.
+              rv = cache_->CalculateSizeOfEntriesBetween(
+                  base::Time(), base::Time::Max(),
+                  base::Bind(
+                      &StoragePartitionHttpCacheDataRemover::
+                          OnCalculationComplete,
+                      base::Unretained(this)));
+            } else {
+              rv = cache_->DoomAllEntries(base::Bind(
+                  &StoragePartitionHttpCacheDataRemover::DoClearCache,
+                  base::Unretained(this)));
+            }
           } else {
-            rv = cache_->DoomEntriesBetween(
-                delete_begin_, delete_end_,
-                base::Bind(&StoragePartitionHttpCacheDataRemover::DoClearCache,
-                           base::Unretained(this)));
+            if (count_only_) {
+              rv = cache_->CalculateSizeOfEntriesBetween(
+                  delete_begin_, delete_end_,
+                  base::Bind(
+                      &StoragePartitionHttpCacheDataRemover::
+                          OnCalculationComplete,
+                      base::Unretained(this)));
+            } else {
+              rv = cache_->DoomEntriesBetween(
+                  delete_begin_, delete_end_,
+                  base::Bind(
+                      &StoragePartitionHttpCacheDataRemover::DoClearCache,
+                      base::Unretained(this)));
+            }
           }
           cache_ = NULL;
         }
@@ -158,4 +204,17 @@ void StoragePartitionHttpCacheDataRemover::DoClearCache(int rv) {
   }
 }
 
+void StoragePartitionHttpCacheDataRemover::OnCalculationComplete(int rv) {
+  // If the calculation was successful, add the size to the sum. If it was not,
+  // finish and return the error code.
+  if (rv < 0) {
+    calculation_result_ = rv;
+    next_cache_state_ = STATE_DONE;
+    DoClearCache(rv);
+  } else {
+    calculation_result_ += rv;
+    DoClearCache(net::OK);
+  }
+}
+
 }  // namespace browsing_data