Bug 1231793: Part 1 - Added read functions for Little Endian integers to ByteReader.h. r=jya

media/libstagefright/binding/include/mp4_demuxer/ByteReader.h

@@ -87,6 +87,16 @@ public:
     return mozilla::BigEndian::readUint16(ptr);
   }
 
+  int16_t ReadLE16()
+  {
+    auto ptr = Read(2);
+    if (!ptr) {
+      MOZ_ASSERT(false);
+      return 0;
+    }
+    return mozilla::LittleEndian::readInt16(ptr);
+  }
+
   uint32_t ReadU24()
   {
     auto ptr = Read(3);
@@ -102,6 +112,20 @@ public:
     return (uint32_t)ReadU24();
   }
 
+  int32_t ReadLE24()
+  {
+    auto ptr = Read(3);
+    if (!ptr) {
+      MOZ_ASSERT(false);
+      return 0;
+    }
+    int32_t result = int32_t(ptr[2] << 16 | ptr[1] << 8 | ptr[0]);
+    if (result & 0x00800000u) {
+      result -= 0x1000000;
+    }
+    return result;
+  }
+
   bool CanRead32() { return mRemaining >= 4; }
 
   uint32_t ReadU32()