Implement tex{Sub}Image{2|3}D with ArrayBufferView sub source.

third_party/WebKit/Source/wtf/typed_arrays/TypedArrayBase.h

Index: third_party/WebKit/Source/wtf/typed_arrays/TypedArrayBase.h
diff --git a/third_party/WebKit/Source/wtf/typed_arrays/TypedArrayBase.h b/third_party/WebKit/Source/wtf/typed_arrays/TypedArrayBase.h
index 2dffab2b431f3ff5d6e88a29acd3c240c00d4dbf..41702047266751c50a3817542dbdd5456c2e3404 100644
--- a/third_party/WebKit/Source/wtf/typed_arrays/TypedArrayBase.h
+++ b/third_party/WebKit/Source/wtf/typed_arrays/TypedArrayBase.h
@@ -57,6 +57,11 @@ public:
         return m_length * sizeof(T);
     }
 
+    unsigned typeSize() const final
+    {
+        return sizeof(T);
+    }
+
     // Invoked by the indexed getter. Does not perform range checks; caller
     // is responsible for doing so and returning undefined as necessary.
     T item(unsigned index) const