Fix the broken build of omxjpegdecoder: http://b/2299035.

1) Add the include path for jni.h.

2) Rename InitCheck() and read_at() to initCheck() and readAt(),
   repectively in StreamSource, as done in DataSource.

3) Add back the definition of SkJPEGImageDecoder to jpeg_decoder_bench.cpp.
   Need to do so because SkJPEGImageDecoder is not defined in a header file.

media/tests/omxjpegdecoder/Android.mk

@@ -34,6 +34,7 @@ LOCAL_SHARED_LIBRARIES := \
     libstagefright
 
 LOCAL_C_INCLUDES := \
+    $(JNI_H_INCLUDE) \
     $(TOP)/external/jpeg \
     $(TOP)/external/skia/include/config \
     $(TOP)/external/skia/include/core \

media/tests/omxjpegdecoder/StreamSource.cpp

@@ -31,11 +31,11 @@ StreamSource::~StreamSource() {
     mStream = NULL;
 }
 
-status_t StreamSource::InitCheck() const {
+status_t StreamSource::initCheck() const {
     return mStream != NULL ? OK : NO_INIT;
 }
 
-ssize_t StreamSource::read_at(off_t offset, void *data, size_t size) {
+ssize_t StreamSource::readAt(off_t offset, void *data, size_t size) {
     Mutex::Autolock autoLock(mLock);
 
     mStream->rewind();

media/tests/omxjpegdecoder/StreamSource.h

@@ -31,8 +31,8 @@ class StreamSource : public DataSource {
 public:
     // Pass the ownership of SkStream to StreamSource.
     StreamSource(SkStream *SkStream);
-    status_t InitCheck() const;
-    virtual ssize_t read_at(off_t offset, void *data, size_t size);
+    virtual status_t initCheck() const;
+    virtual ssize_t readAt(off_t offset, void *data, size_t size);
     virtual status_t getSize(off_t *size);
 
 protected:

media/tests/omxjpegdecoder/jpeg_decoder_bench.cpp

@@ -25,6 +25,17 @@
 #include "SkStream.h"
 #include "omx_jpeg_decoder.h"
 
+class SkJPEGImageDecoder : public SkImageDecoder {
+public:
+    virtual Format getFormat() const {
+        return kJPEG_Format;
+    }
+
+protected:
+    virtual bool onDecode(SkStream* stream, SkBitmap* bm,
+                          SkBitmap::Config pref, Mode);
+};
+
 int nullObjectReturn(const char msg[]) {
     if (msg) {
         SkDebugf("--- %s\n", msg);