A blind fix for Issue 18837 (and a build fix for VS2008)

To read this crash dump, this issue is caused by my mistake that this jumplist.cc calls "icon_urls_.front()" for an empty list.
This change added some checks that verifies a std::list has one or more items.
This change also fixes linker errors because of conflicted symbols: CLSID_DestinationList and CLSID_EnumerableObjectCollection, which is caused by my mistake that I forgot removing "EXTERN_C" keywords when I moved them into an anonymous namespace. This change removes the "EXTERN_C" keywords for VS2008.

BUG=18837 "Crash - JumpList::OnFavIconDataAvailable(int,bool,scoped_refptr<RefCountedVector<unsigned char> >,bool,GURL)"
TEST=Show JumpList on Windows 7.
TEST=Build Chromium with VS2008.
Review URL: http://codereview.chromium.org/159853

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@22907 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 10 insertions, 7 deletions

diff --git a/chrome/browser/jumplist.cc b/chrome/browser/jumplist.cc
index fcf39e6..81342aa 100644
--- a/chrome/browser/jumplist.cc
+++ b/chrome/browser/jumplist.cc
@@ -109,14 +109,14 @@ ICustomDestinationList : public IUnknown {
 #endif  // __ICustomDestinationList_INTERFACE_DEFINED__
 
 // Class IDs used in this file.
-// These class IDs should be defined in an anonymous namespace to avoid
-// potential conflicts with ones defined in "shell32.lib" of Microsoft SDK 7.0.
+// These class IDs must be defined in an anonymous namespace to avoid
+// conflicts with ones defined in "shell32.lib" of Visual Studio 2008.
 // TODO(hbono): Bug 16903: to be deleted them when we use Windows SDK 7.0.
-EXTERN_C const CLSID CLSID_DestinationList = {
+const CLSID CLSID_DestinationList = {
   0x77f10cf0, 0x3db5, 0x4966, {0xb5, 0x20, 0xb7, 0xc5, 0x4f, 0xd3, 0x5e, 0xd6}
 };
 
-EXTERN_C const CLSID CLSID_EnumerableObjectCollection = {
+const CLSID CLSID_EnumerableObjectCollection = {
   0x2d3468c1, 0x36a7, 0x43b6, {0xac, 0x24, 0xd3, 0xf0, 0x2f, 0xd9, 0x60, 0x7a}
 };
 
@@ -712,11 +712,14 @@ void JumpList::OnFavIconDataAvailable(
     GURL icon_url) {
   // Attach the received data to the ShellLinkItem object.
   // This data will be decoded by JumpListUpdateTask.
-  if (know_favicon && data.get() && !data->data.empty())
-    icon_urls_.front().second->SetIconData(data);
+  if (know_favicon && data.get() && !data->data.empty()) {
+    if (!icon_urls_.empty() && icon_urls_.front().second)
+      icon_urls_.front().second->SetIconData(data);
+  }
 
   // if we need to load more fav icons, we send another query and exit.
-  icon_urls_.pop_front();
+  if (!icon_urls_.empty())
+    icon_urls_.pop_front();
   if (StartLoadingFavIcon())
     return;