Fix out-of-memory crashes related to ArrayBuffer allocation

third_party/WebKit/Source/wtf/ArrayBufferBuilder.h

Index: third_party/WebKit/Source/wtf/ArrayBufferBuilder.h
diff --git a/third_party/WebKit/Source/wtf/ArrayBufferBuilder.h b/third_party/WebKit/Source/wtf/ArrayBufferBuilder.h
index 38b285a0bf02dbec54bda02d7985b31e80899bda..2a6cf747aa74301a221b280b52c968496df129e7 100644
--- a/third_party/WebKit/Source/wtf/ArrayBufferBuilder.h
+++ b/third_party/WebKit/Source/wtf/ArrayBufferBuilder.h
@@ -53,7 +53,7 @@ public:
         : m_bytesUsed(0)
         , m_variableCapacity(true)
     {
-        m_buffer = ArrayBuffer::create(capacity, 1);
+        m_buffer = ArrayBuffer::createOrNull(capacity, 1);
     }
 
     bool isValid() const
@@ -82,6 +82,7 @@ public:
     // Number of bytes allocated.
     unsigned capacity() const
     {
+        ASSERT(isValid());
         return m_buffer->byteLength();
     }
 
@@ -89,6 +90,7 @@ public:
 
     const void* data() const
     {
+        ASSERT(isValid());
         return m_buffer->data();
     }