Bump up the number of simultaneous connections in IE to 6. This is done via a WinInet API

InternetSetOption.

Fixes bug http://code.google.com/p/chromium/issues/detail?id=50328

BUG=50328
TEST=none

Review URL: http://codereview.chromium.org/6480092

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@75162 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 46 insertions, 0 deletions

diff --git a/chrome_frame/bho.cc b/chrome_frame/bho.cc
index 0cd3a4a..62f9079 100644
--- a/chrome_frame/bho.cc
+++ b/chrome_frame/bho.cc
@@ -25,6 +25,7 @@
 #include "chrome_frame/vtable_patch_manager.h"
 
 static const int kIBrowserServiceOnHttpEquivIndex = 30;
+static const DWORD kMaxHttpConnections = 6;
 
 PatchHelper g_patch_helper;
 
@@ -136,6 +137,11 @@ STDMETHODIMP Bho::SetSite(IUnknown* site) {
     AddRef();
     RegisterThreadInstance();
     MetricsService::Start();
+
+    if (!IncreaseWinInetConnections(kMaxHttpConnections)) {
+      DLOG(WARNING) << "Failed to bump up HTTP connections. Error:"
+                    << ::GetLastError();
+    }
   } else {
     UnregisterThreadInstance();
     buggy_bho::BuggyBhoTls::DestroyInstance();
diff --git a/chrome_frame/utils.cc b/chrome_frame/utils.cc
index 049294c..7182428 100644
--- a/chrome_frame/utils.cc
+++ b/chrome_frame/utils.cc
@@ -1603,3 +1603,36 @@ bool IsChromeFrameDocument(IWebBrowser2* web_browser) {
   return false;
 }
 
+bool IncreaseWinInetConnections(DWORD connections) {
+  static bool wininet_connection_count_updated = false;
+  if (wininet_connection_count_updated) {
+    return true;
+  }
+
+  static int connection_options[] = {
+    INTERNET_OPTION_MAX_CONNS_PER_SERVER,
+    INTERNET_OPTION_MAX_CONNS_PER_1_0_SERVER,
+  };
+
+  BOOL ret = FALSE;
+
+  for (int option_index = 0; option_index < arraysize(connection_options);
+       ++option_index) {
+    DWORD connection_value_size = sizeof(DWORD);
+    DWORD current_connection_limit = 0;
+    InternetQueryOption(NULL, connection_options[option_index],
+                        &current_connection_limit, &connection_value_size);
+    if (current_connection_limit > connections) {
+      continue;
+    }
+
+    ret = InternetSetOption(NULL, connection_options[option_index],
+                            &connections, connection_value_size);
+    if (!ret) {
+      return false;
+    }
+  }
+  wininet_connection_count_updated = true;
+  return true;
+}
+
diff --git a/chrome_frame/utils.h b/chrome_frame/utils.h
index 5847917..47f0929 100644
--- a/chrome_frame/utils.h
+++ b/chrome_frame/utils.h
@@ -618,4 +618,11 @@ std::wstring GetCurrentModuleVersion();
 // Returns true if ChromeFrame is the currently loaded document.
 bool IsChromeFrameDocument(IWebBrowser2* web_browser);
 
+// Increases the wininet connection limit for HTTP 1.0/1.1 connections to the
+// value passed in. This is only done if the existing connection limit is
+// lesser than the connection limit passed in. This function attempts to
+// increase the connection count once per process.
+// Returns true on success.
+bool IncreaseWinInetConnections(DWORD connections);
+
 #endif  // CHROME_FRAME_UTILS_H_