SPDY flow control: enforce obeying send window size via a command-line switch, initial support for receive window size.

BUG=48100
TEST=net_unittestss --gtest_filter="SpdyProtocolTest.ControlFrameStructs:SpdyNetworkTransactionTest.WindowUpdate:SpdyNetworkTransactionTest.WindowUpdateOverflow"

Review URL: http://codereview.chromium.org/3052005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@53297 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 11 insertions, 1 deletions

diff --git a/net/http/http_network_layer.cc b/net/http/http_network_layer.cc
index 7df286f..4950a7b 100644
--- a/net/http/http_network_layer.cc
+++ b/net/http/http_network_layer.cc
@@ -130,6 +130,12 @@ void HttpNetworkLayer::EnableSpdy(const std::string& mode) {
   static const char kDisableCompression[] = "no-compress";
   static const char kDisableAltProtocols[] = "no-alt-protocols";
 
+  // If flow-control is enabled, received WINDOW_UPDATE and SETTINGS
+  // messages are processed and outstanding window size is actually obeyed
+  // when sending data frames, and WINDOW_UPDATE messages are generated
+  // when data is consumed.
+  static const char kEnableFlowControl[] = "flow-control";
+
   // We want an A/B experiment between SPDY enabled and SPDY disabled,
   // but only for pages where SPDY *could have been* negotiated.  To do
   // this, we use NPN, but prevent it from negotiating SPDY.  If the
@@ -179,6 +185,8 @@ void HttpNetworkLayer::EnableSpdy(const std::string& mode) {
     } else if (option == kDisableAltProtocols) {
       use_alt_protocols = false;
       HttpNetworkTransaction::SetUseAlternateProtocols(false);
+    } else if (option == kEnableFlowControl) {
+      SpdySession::SetFlowControl(true);
     } else if (option.empty() && it == spdy_options.begin()) {
       continue;
     } else {
diff --git a/net/http/http_network_layer.h b/net/http/http_network_layer.h
index 8cc62ab..657fcd3 100644
--- a/net/http/http_network_layer.h
+++ b/net/http/http_network_layer.h
@@ -66,9 +66,11 @@ class HttpNetworkLayer : public HttpTransactionFactory, public NonThreadSafe {
 
   // Enable the spdy protocol.
   // Without calling this function, SPDY is disabled.  The mode can be:
-  //   ""            : (default) SSL and compression are enabled.
+  //   ""            : (default) SSL and compression are enabled, flow
+  //                   control disabled.
   //   "no-ssl"      : disables SSL.
   //   "no-compress" : disables compression.
+  //   "flow-control": enables flow control.
   //   "none"        : disables both SSL and compression.
   static void EnableSpdy(const std::string& mode);