Move PdfDocument to android.graphics.pdf

1. Move PdfDocument to android.graphics.pdf.

2. Changed the PdfDocument as per API concil request.

3. Updated the documentation.

bug:10461180
bug:10552565
bug:10681585
bug:10552336

Change-Id: I08e15b34cf37bb064248c887e6f59808019cafe8
diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index 490d85c..8518101 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -117,6 +117,7 @@
 extern int register_android_graphics_Region(JNIEnv* env);
 extern int register_android_graphics_SurfaceTexture(JNIEnv* env);
 extern int register_android_graphics_Xfermode(JNIEnv* env);
+extern int register_android_graphics_pdf_PdfDocument(JNIEnv* env);
 extern int register_android_view_DisplayEventReceiver(JNIEnv* env);
 extern int register_android_view_GraphicBuffer(JNIEnv* env);
 extern int register_android_view_GLES20DisplayList(JNIEnv* env);
@@ -144,7 +145,6 @@
 extern int register_android_os_FileUtils(JNIEnv *env);
 extern int register_android_os_UEventObserver(JNIEnv* env);
 extern int register_android_os_MemoryFile(JNIEnv* env);
-extern int register_android_print_pdf_PdfDocument(JNIEnv* env);
 extern int register_android_net_LocalSocketImpl(JNIEnv* env);
 extern int register_android_net_NetworkUtils(JNIEnv* env);
 extern int register_android_net_TrafficStats(JNIEnv* env);
@@ -1161,6 +1161,7 @@
     REG_JNI(register_android_graphics_Typeface),
     REG_JNI(register_android_graphics_Xfermode),
     REG_JNI(register_android_graphics_YuvImage),
+    REG_JNI(register_android_graphics_pdf_PdfDocument),
 
     REG_JNI(register_android_database_CursorWindow),
     REG_JNI(register_android_database_SQLiteConnection),
@@ -1173,7 +1174,6 @@
     REG_JNI(register_android_os_SELinux),
     REG_JNI(register_android_os_Trace),
     REG_JNI(register_android_os_UEventObserver),
-    REG_JNI(register_android_print_pdf_PdfDocument),
     REG_JNI(register_android_net_LocalSocketImpl),
     REG_JNI(register_android_net_NetworkUtils),
     REG_JNI(register_android_net_TrafficStats),