Add 'cbcs' encryption scheme support in Android media.

media/base/android/java/src/org/chromium/media/MediaCodecUtil.java

Index: media/base/android/java/src/org/chromium/media/MediaCodecUtil.java
diff --git a/media/base/android/java/src/org/chromium/media/MediaCodecUtil.java b/media/base/android/java/src/org/chromium/media/MediaCodecUtil.java
index 5bda3df60c9b0e6abe2797e20d21738b4b17f1a5..93295f87c1e59cb450f20f24c930467bb24fd7bd 100644
--- a/media/base/android/java/src/org/chromium/media/MediaCodecUtil.java
+++ b/media/base/android/java/src/org/chromium/media/MediaCodecUtil.java
@@ -15,6 +15,9 @@ import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.MainDex;
 
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.Locale;
 
 /**
@@ -322,4 +325,73 @@ class MediaCodecUtil {
         }
         return false;
     }
+
+    static boolean trySetCryptoInfoPattern(
+            MediaCodec.CryptoInfo cryptoInfo, int encrypt, int skip) {
+        if (sMediaCodecCryptoInfoPatternCtor == null
+                || sMediaCodecCryptoInfoSetPatternMethod == null) {
+            return false;
+        }
+        Object pattern;
+        try {
+            pattern = sMediaCodecCryptoInfoPatternCtor.newInstance(encrypt, skip);
+        } catch (IllegalAccessException e) {
+            Log.e(TAG, "Cannot construct Pattern instance.", e);
+            return false;
+        } catch (InstantiationException e) {
+            Log.e(TAG, "Cannot construct Pattern instance.", e);
+            return false;
+        } catch (InvocationTargetException e) {
+            Log.e(TAG, "Cannot construct Pattern instance.", e);
+            return false;
+        }
+        try {
+            sMediaCodecCryptoInfoSetPatternMethod.invoke(cryptoInfo, pattern);
+            return true;
+        } catch (NullPointerException e) {
+            Log.e(TAG, "Cannot call setPattern method.", e);
+        } catch (IllegalAccessException e) {
+            Log.e(TAG, "Cannot call setPattern method.", e);
+        } catch (IllegalArgumentException e) {
+            Log.e(TAG, "Cannot call setPattern method.", e);
+        } catch (InvocationTargetException e) {
+            Log.e(TAG, "Cannot call setPattern method.", e);
+        }
+        return false;
+    }
+
+    static {
+        initMediaCodecCryptoInfoPatternMethods();
+    }
+
+    private static void initMediaCodecCryptoInfoPatternMethods() {
+        Class<?> cryptoInfoClazz = MediaCodec.CryptoInfo.class;
+        Class<?> cryptoInfoPatternClazz = null;
+        for (Class<?> clazz : cryptoInfoClazz.getClasses()) {
+            if (clazz.getSimpleName().equals(PATTERN_CLASS_SIMPLE_NAME)) {
+                cryptoInfoPatternClazz = clazz;
+                break;
+            }
+        }
+        if (cryptoInfoPatternClazz == null) return;
+        try {
+            sMediaCodecCryptoInfoPatternCtor =
+                    cryptoInfoPatternClazz.getConstructor(int.class, int.class);

[xhwang, 2016/06/15 05:29:05]

Can you just check the API level instead of using reflections? You may want to
add an Android owner for this kind of questions.

Here's how we check the API level in MediaDrmBridge:
https://cs.chromium.org/chromium/src/media/base/android/java/src/org/chromium...

[dougsteed, 2016/06/15 17:57:38]

As I am accessing a new method only added in N, I can't do that until the N SDK
is added to chromium. Also I need the Build.VERSION enumeration to be updated.
In the meantime, I can code this up and hopefully get this working using
reflection, which makes it is extremely convenient.
Once the SDK is in chromium, I will be happy to change this. Might possibly wait
until that happens before merging this.
(I am not the right person and I don't think it is yet the time to actually make
those updates).

[dougsteed, 2016/10/20 17:07:35]

Android N SDK has now been added to chromium, so I now fixed this.

+        } catch (NoSuchMethodException e) {
+            Log.e(TAG, "Cannot find MediaCodec.CryptInfo.Pattern constructor", e);

[xhwang, 2016/06/15 05:29:05]

s/CryptInfo/CryptoInfo

+            return;
+        }
+        try {
+            sMediaCodecCryptoInfoSetPatternMethod =
+                    cryptoInfoClazz.getMethod(SET_PATTERN_METHOD_NAME, cryptoInfoPatternClazz);
+        } catch (NoSuchMethodException e) {
+            Log.e(TAG, "Cannot access MediaCodec.CryptInfo.setPattern method", e);

[xhwang, 2016/06/15 05:29:05]

ditto

+            return;
+        }
+    }
+
+    static final String PATTERN_CLASS_SIMPLE_NAME = "Pattern";
+    static final String SET_PATTERN_METHOD_NAME = "setPattern";
+    static Method sMediaCodecCryptoInfoSetPatternMethod;
+    static Constructor<?> sMediaCodecCryptoInfoPatternCtor;
 }