Fix potential bug in FastSharedBufferReader::getConsecutiveData

Source/platform/image-decoders/FastSharedBufferReader.h

Index: Source/platform/image-decoders/FastSharedBufferReader.h
diff --git a/Source/platform/image-decoders/FastSharedBufferReader.h b/Source/platform/image-decoders/FastSharedBufferReader.h
index 1add43037db0de7d83767a74ac8eb40fcea09ce9..36b84b67bc005b84a894bc421547c16d3fdb55c3 100644
--- a/Source/platform/image-decoders/FastSharedBufferReader.h
+++ b/Source/platform/image-decoders/FastSharedBufferReader.h
@@ -70,15 +70,21 @@ public:
     }
 
 private:
+    void getSomeDataIntoCache(unsigned dataPosition);
+
     RefPtr<SharedBuffer> m_data;
 
-    // Caches the last segment of |m_data| accessed, since subsequent reads are
-    // likely to re-access it.
-    const char* m_segment;
-    size_t m_segmentLength;
+    struct Cache {

[Peter Kasting, 2015/03/25 19:53:11]

I don't see what adding this struct buys other than more verbosity.

+        Cache();
+
+        // Caches the last segment of |m_data| accessed, since subsequent reads are
+        // likely to re-access it.
+        const char* segment;
+        size_t segmentLength;
 
-    // Data position in |m_data| pointed by |m_segment|.
-    size_t m_dataPosition;
+        // Data position in |m_data| pointed by |segment|.
+        size_t dataPosition;
+    } m_cache;
 };
 
 } // namespace blink