Adding minimal error checking to ScopedCOMInitializer.

Review URL: http://codereview.chromium.org/17348

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7860 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 19 insertions, 6 deletions

diff --git a/chrome/common/win_util.cc b/chrome/common/win_util.cc
index 1c552a2..6af0db8 100644
--- a/chrome/common/win_util.cc
+++ b/chrome/common/win_util.cc
@@ -82,6 +82,15 @@ UINT_PTR CALLBACK SaveAsDialogHook(HWND dialog, UINT message,
 
 }  // namespace
 
+ScopedCOMInitializer::ScopedCOMInitializer() : hr_(CoInitialize(NULL)) {
+  DCHECK(hr_ != RPC_E_CHANGED_MODE) << "thread already initialized as MTA";
+}
+
+ScopedCOMInitializer::~ScopedCOMInitializer() {
+  if (SUCCEEDED(hr_))
+    CoUninitialize();
+}
+
 std::wstring FormatSystemTime(const SYSTEMTIME& time,
                               const std::wstring& format) {
   // If the format string is empty, just use the default format.
diff --git a/chrome/common/win_util.h b/chrome/common/win_util.h
index 5487ef3..02a8ace 100644
--- a/chrome/common/win_util.h
+++ b/chrome/common/win_util.h
@@ -57,18 +57,22 @@ class CoMemReleaser {
   DISALLOW_COPY_AND_ASSIGN(CoMemReleaser);
 };
 
-// Initializes COM in the constructor, and uninitializes COM in the
+// Initializes COM in the constructor (STA), and uninitializes COM in the
 // destructor.
 class ScopedCOMInitializer {
  public:
-  ScopedCOMInitializer() {
-    CoInitialize(NULL);
-  }
+  ScopedCOMInitializer();
+  ~ScopedCOMInitializer();
 
-  ~ScopedCOMInitializer() {
-    CoUninitialize();
+  // Returns the error code from CoInitialize(NULL)
+  // (called in constructor)
+  inline HRESULT error_code() const {
+    return hr_;
   }
 
+ protected:
+  HRESULT hr_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ScopedCOMInitializer);
 };