Improve libjingle's ASSERT and VERIFY macros on Windows.
This change has the effect that when using a debugger, a failing ASSERT/VERIFY will break exactly where the failing expression is and not two callstacks up.
Minidumps (for debug builds) will also have the failing expression at the top of the call stack.

R=xians@webrtc.org, xians

Review URL: https://webrtc-codereview.appspot.com/12929004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6633 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/base/common.h b/talk/base/common.h
index ed7d59e..be0e89d 100644
--- a/talk/base/common.h
+++ b/talk/base/common.h
@@ -131,9 +131,17 @@
   if (!result) {
     LogAssert(function, file, line, expression);
     Break();
-    return false;
   }
-  return true;
+  return result;
+}
+
+// Same as Assert above, but does not call Break().  Used in assert macros
+// that implement their own breaking.
+inline bool AssertNoBreak(bool result, const char* function, const char* file,
+                          int line, const char* expression) {
+  if (!result)
+    LogAssert(function, file, line, expression);
+  return result;
 }
 
 }  // namespace talk_base
@@ -143,13 +151,28 @@
 #endif
 
 #ifndef ASSERT
+#if defined(WIN32)
+// Using debugbreak() inline on Windows directly in the ASSERT macro, has the
+// benefit of breaking exactly where the failing expression is and not two
+// calls up the stack.
+#define ASSERT(x) \
+    (talk_base::AssertNoBreak((x), __FUNCTION__, __FILE__, __LINE__, #x) ? \
+     (void)(1) : __debugbreak())
+#else
 #define ASSERT(x) \
     (void)talk_base::Assert((x), __FUNCTION__, __FILE__, __LINE__, #x)
 #endif
+#endif
 
 #ifndef VERIFY
+#if defined(WIN32)
+#define VERIFY(x) \
+    (talk_base::AssertNoBreak((x), __FUNCTION__, __FILE__, __LINE__, #x) ? \
+     true : (__debugbreak(), false))
+#else
 #define VERIFY(x) talk_base::Assert((x), __FUNCTION__, __FILE__, __LINE__, #x)
 #endif
+#endif
 
 #else  // !ENABLE_DEBUG