Turn ASSERTs in platform setup releated code into CHECKs

This way, we will already catch misconfigurations in release builds,
instead of getting random bug reports way later during runtime.

BUG=none
R=jkummerow@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/429203002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/v8.cc

@@ -103,14 +103,14 @@ void V8::InitializeOncePerProcess() {
 
 
 void V8::InitializePlatform(v8::Platform* platform) {
-  ASSERT(!platform_);
-  ASSERT(platform);
+  CHECK(!platform_);
+  CHECK(platform);
   platform_ = platform;
 }
 
 
 void V8::ShutdownPlatform() {
-  ASSERT(platform_);
+  CHECK(platform_);
   platform_ = NULL;
 }