Revert 84096 - Merge 84071 - Defer asynchronous loading when the buffer in PPB_URLLoader_Impl exceeds an optionally-specified threshold and re-enable it when the buffer drops below a lower threshold.

BUG=80684
TEST=Set the thresholds to 4 MB and 2 MB, respectively from a plugin then download a large file (> 200 MB). Observe that the renderer/plugin process memory usage in Task Manager does not exceed ~100MB and that network traffic drops to 0 then picks up again briefly after 10 MB are used.

Review URL: http://codereview.chromium.org/6923002

TBR=ddorwin@chromium.org
Review URL: http://codereview.chromium.org/6928014

TBR=ddorwin@chromium.org
Review URL: http://codereview.chromium.org/6931025

git-svn-id: svn://svn.chromium.org/chrome/branches/742/src@84191 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 1 insertions, 70 deletions

diff --git a/webkit/plugins/ppapi/ppb_url_loader_impl.cc b/webkit/plugins/ppapi/ppb_url_loader_impl.cc
index 5684d40..27ec617 100644
--- a/webkit/plugins/ppapi/ppb_url_loader_impl.cc
+++ b/webkit/plugins/ppapi/ppb_url_loader_impl.cc
@@ -208,8 +208,6 @@ PPB_URLLoader_Impl::PPB_URLLoader_Impl(PluginInstance* instance,
       user_buffer_(NULL),
       user_buffer_size_(0),
       done_status_(PP_OK_COMPLETIONPENDING),
-      is_streaming_to_file_(false),
-      is_asynchronous_load_suspended_(false),
       has_universal_access_(false),
       status_callback_(NULL) {
 }
@@ -270,7 +268,6 @@ int32_t PPB_URLLoader_Impl::Open(PPB_URLRequestInfo_Impl* request,
     options.allowCredentials = request->allow_credentials();
   }
 
-  is_asynchronous_load_suspended_ = false;
   loader_.reset(frame->createAssociatedURLLoader(options));
   if (!loader_.get())
     return PP_ERROR_FAILED;
@@ -368,12 +365,6 @@ int32_t PPB_URLLoader_Impl::FinishStreamingToFile(
   if (done_status_ != PP_OK_COMPLETIONPENDING)
     return done_status_;
 
-  is_streaming_to_file_ = true;
-  if (is_asynchronous_load_suspended_) {
-    loader_->setDefersLoading(false);
-    is_asynchronous_load_suspended_ = false;
-  }
-
   // Wait for didFinishLoading / didFail.
   RegisterCallback(callback);
   return PP_OK_COMPLETIONPENDING;
@@ -449,20 +440,6 @@ void PPB_URLLoader_Impl::didReceiveData(WebURLLoader* loader,
   } else {
     DCHECK(!pending_callback_.get() || pending_callback_->completed());
   }
-
-  // To avoid letting the network stack download an entire stream all at once,
-  // defer loading when we have enough buffer.
-  // Check the buffer size after potentially moving some to the user buffer.
-  DCHECK(request_info_->prefetch_buffer_lower_threshold() <
-         request_info_->prefetch_buffer_upper_threshold());
-  if (!is_streaming_to_file_ &&
-      !is_asynchronous_load_suspended_ &&
-      buffer_.size() >= static_cast<size_t>(
-          request_info_->prefetch_buffer_upper_threshold())) {
-    DVLOG(1) << "Suspending async load - buffer size: " << buffer_.size();
-    loader->setDefersLoading(true);
-    is_asynchronous_load_suspended_ = true;
-  }
 }
 
 void PPB_URLLoader_Impl::didFinishLoading(WebURLLoader* loader,
@@ -521,15 +498,6 @@ size_t PPB_URLLoader_Impl::FillUserBuffer() {
   std::copy(buffer_.begin(), buffer_.begin() + bytes_to_copy, user_buffer_);
   buffer_.erase(buffer_.begin(), buffer_.begin() + bytes_to_copy);
 
-  // If the buffer is getting too empty, resume asynchronous loading.
-  if (is_asynchronous_load_suspended_ &&
-      buffer_.size() <= static_cast<size_t>(
-          request_info_->prefetch_buffer_lower_threshold())) {
-    DVLOG(1) << "Resuming async load - buffer size: " << buffer_.size();
-    loader_->setDefersLoading(false);
-    is_asynchronous_load_suspended_ = false;
-  }
-
   // Reset for next time.
   user_buffer_ = NULL;
   user_buffer_size_ = 0;
diff --git a/webkit/plugins/ppapi/ppb_url_loader_impl.h b/webkit/plugins/ppapi/ppb_url_loader_impl.h
index 878ce65..fae3628 100644
--- a/webkit/plugins/ppapi/ppb_url_loader_impl.h
+++ b/webkit/plugins/ppapi/ppb_url_loader_impl.h
@@ -137,8 +137,6 @@ class PPB_URLLoader_Impl : public Resource, public WebKit::WebURLLoaderClient {
   char* user_buffer_;
   size_t user_buffer_size_;
   int32_t done_status_;
-  bool is_streaming_to_file_;
-  bool is_asynchronous_load_suspended_;
 
   bool has_universal_access_;
 
diff --git a/webkit/plugins/ppapi/ppb_url_request_info_impl.cc b/webkit/plugins/ppapi/ppb_url_request_info_impl.cc
index 90a0ec6..7bae8ba 100644
--- a/webkit/plugins/ppapi/ppb_url_request_info_impl.cc
+++ b/webkit/plugins/ppapi/ppb_url_request_info_impl.cc
@@ -34,9 +34,6 @@ namespace ppapi {
 
 namespace {
 
-const int32_t kDefaultPrefetchBufferUpperThreshold = 100 * 1000 * 1000;
-const int32_t kDefaultPrefetchBufferLowerThreshold = 50 * 1000 * 1000;
-
 // A header string containing any of the following fields will cause
 // an error. The list comes from the XMLHttpRequest standard.
 // http://www.w3.org/TR/XMLHttpRequest/#the-setrequestheader-method
@@ -116,10 +113,6 @@ PP_Bool SetProperty(PP_Resource request_id,
           request->SetBooleanProperty(property,
                                       PPBoolToBool(var.value.as_bool)));
       break;
-    case PP_VARTYPE_INT32:
-      result = BoolToPPBool(
-          request->SetIntegerProperty(property, var.value.as_int));
-      break;
     case PP_VARTYPE_STRING: {
       scoped_refptr<StringVar> string(StringVar::FromPPVar(var));
       if (string)
@@ -210,9 +203,7 @@ PPB_URLRequestInfo_Impl::PPB_URLRequestInfo_Impl(PluginInstance* instance)
       has_custom_referrer_url_(false),
       allow_cross_origin_requests_(false),
       allow_credentials_(false),
-      has_custom_content_transfer_encoding_(false),
-      prefetch_buffer_upper_threshold_(kDefaultPrefetchBufferUpperThreshold),
-      prefetch_buffer_lower_threshold_(kDefaultPrefetchBufferLowerThreshold) {
+      has_custom_content_transfer_encoding_(false) {
 }
 
 PPB_URLRequestInfo_Impl::~PPB_URLRequestInfo_Impl() {
@@ -269,20 +260,6 @@ bool PPB_URLRequestInfo_Impl::SetBooleanProperty(PP_URLRequestProperty property,
   }
 }
 
-bool PPB_URLRequestInfo_Impl::SetIntegerProperty(PP_URLRequestProperty property,
-                                                 int32_t value) {
-  switch (property) {
-    case PP_URLREQUESTPROPERTY_PREFETCHBUFFERUPPERTHRESHOLD:
-      prefetch_buffer_upper_threshold_ = value;
-      return true;
-    case PP_URLREQUESTPROPERTY_PREFETCHBUFFERLOWERTHRESHOLD:
-      prefetch_buffer_lower_threshold_ = value;
-      return true;
-    default:
-      return false;
-  }
-}
-
 bool PPB_URLRequestInfo_Impl::SetStringProperty(PP_URLRequestProperty property,
                                                 const std::string& value) {
   // TODO(darin): Validate input.  Perhaps at a different layer?
diff --git a/webkit/plugins/ppapi/ppb_url_request_info_impl.h b/webkit/plugins/ppapi/ppb_url_request_info_impl.h
index 2cdf3e4..9d6c766 100644
--- a/webkit/plugins/ppapi/ppb_url_request_info_impl.h
+++ b/webkit/plugins/ppapi/ppb_url_request_info_impl.h
@@ -37,7 +37,6 @@ class PPB_URLRequestInfo_Impl : public Resource {
   // PPB_URLRequestInfo implementation.
   bool SetUndefinedProperty(PP_URLRequestProperty property);
   bool SetBooleanProperty(PP_URLRequestProperty property, bool value);
-  bool SetIntegerProperty(PP_URLRequestProperty property, int32_t value);
   bool SetStringProperty(PP_URLRequestProperty property,
                          const std::string& value);
   bool AppendDataToBody(const std::string& data);
@@ -61,13 +60,6 @@ class PPB_URLRequestInfo_Impl : public Resource {
   }
   bool allow_credentials() const { return allow_credentials_; }
 
-  int32_t prefetch_buffer_upper_threshold() const {
-      return prefetch_buffer_upper_threshold_;
-  }
-  int32_t prefetch_buffer_lower_threshold() const {
-      return prefetch_buffer_lower_threshold_;
-  }
-
  private:
   struct BodyItem;
   typedef std::vector<BodyItem> Body;
@@ -97,10 +89,6 @@ class PPB_URLRequestInfo_Impl : public Resource {
   bool has_custom_content_transfer_encoding_;
   std::string custom_content_transfer_encoding_;
 
-  // Specify permitted range for the size of the buffer unconsumed by plugin.
-  int32_t prefetch_buffer_upper_threshold_;
-  int32_t prefetch_buffer_lower_threshold_;
-
   DISALLOW_COPY_AND_ASSIGN(PPB_URLRequestInfo_Impl);
 };