Disable checks for b/27493510

Disabled for performance now that the bug is fixed. Still enabled
for debug builds.

Bug: 27493510

(cherry picked from commit 8790c7f9f7d684bff40d5731b2d8e3462ef8ed90)

Change-Id: I049d4319bca1114bd11a35bb13fc9d80c993260c
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index ba935f7..89e8ff2 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -96,7 +96,7 @@
 namespace art {
 static constexpr bool kSanityCheckObjects = kIsDebugBuild;
-static constexpr bool kVerifyArtMethodDeclaringClasses = true;
+static constexpr bool kVerifyArtMethodDeclaringClasses = kIsDebugBuild;
 static void ThrowNoClassDefFoundError(const char* fmt, ...)
     __attribute__((__format__(__printf__, 1, 2)))
diff --git a/runtime/thread.cc b/runtime/thread.cc
index e3adf9f..d8260a8 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -90,8 +90,7 @@
 pthread_key_t Thread::pthread_key_self_;
 ConditionVariable* Thread::resume_cond_ = nullptr;
 const size_t Thread::kStackOverflowImplicitCheckSize = GetStackOverflowReservedBytes(kRuntimeISA);
-// Enabled for b/27493510. TODO: disable when fixed.
-static constexpr bool kVerifyImageObjectsMarked = true;
+static constexpr bool kVerifyImageObjectsMarked = kIsDebugBuild;
 // For implicit overflow checks we reserve an extra piece of memory at the bottom
 // of the stack (lowest memory).  The higher portion of the memory