Manually read stream to byte array in gif decoder.

Doing so means we go from using 3x the necessary
memory in the worst case to 2x, and in the best
case we go from using 2x the necessary memory to
using exactly what we need (for images larger than
the buffer size). 

Progress toward bumptech#83

library/src/androidTest/java/com/bumptech/glide/load/resource/gif/GifResourceDecoderTest.java

@@ -109,7 +109,7 @@ public void testDecodesFirstFrameAndReturnsGifDecoderToPool() {
 
         InOrder order = inOrder(decoderPool, gifDecoder);
         order.verify(decoderPool).obtain(any(GifDecoder.BitmapProvider.class));
-        order.verify(gifDecoder).setData(eq(gifHeader), eq(data));
+        order.verify(gifDecoder).setData(eq(gifHeader), any(byte[].class));
         order.verify(gifDecoder).advance();
         order.verify(gifDecoder).getNextFrame();
         order.verify(decoderPool).release(eq(gifDecoder));

library/src/main/java/com/bumptech/glide/load/resource/gif/GifResourceDecoder.java

@@ -14,7 +14,6 @@
 import com.bumptech.glide.load.resource.UnitTransformation;
 import com.bumptech.glide.util.Util;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Queue;
@@ -24,6 +23,7 @@
  * {@link com.bumptech.glide.load.resource.gif.GifDrawable} from {@link java.io.InputStream} data.
  */
 public class GifResourceDecoder implements ResourceDecoder<InputStream, GifDrawable> {
+    private static final int DEFAULT_BUFFER_BYTE_SIZE = 16384;
     private static final String TAG = "GifResourceDecoder";
     private static final GifHeaderParserPool PARSER_POOL = new GifHeaderParserPool();
     private static final GifDecoderPool DECODER_POOL = new GifDecoderPool();
@@ -97,20 +97,23 @@ public String getId() {
     }
 
     private static byte[] inputStreamToBytes(InputStream is) {
-        final int bufferSize = 16384;
-        ByteArrayOutputStream buffer = new ByteArrayOutputStream(bufferSize);
+        byte[] data = new byte[DEFAULT_BUFFER_BYTE_SIZE];
+        int dataPosition = 0;
         try {
-            int nRead;
-            byte[] data = new byte[bufferSize];
-            while ((nRead = is.read(data)) != -1) {
-                buffer.write(data, 0, nRead);
+            int read;
+            while ((read = is.read(data, dataPosition, data.length - dataPosition)) != -1) {
+                dataPosition += read;
+                if (dataPosition == data.length) {
+                    byte[] temp = new byte[data.length * 2];
+                    System.arraycopy(data, 0, temp, 0, data.length);
+                    data = temp;
+                }
             }
-            buffer.flush();
         } catch (IOException e) {
             Log.w(TAG, "Error reading data from stream", e);
         }
-        //TODO the returned byte[] may be partial if an IOException was thrown from read
-        return buffer.toByteArray();
+        // TODO: the returned byte[] may be partial if an IOException was thrown from read
+        return data;
     }
 
     // Visible for testing.

samples/giphy/src/main/AndroidManifest.xml

@@ -6,7 +6,6 @@
     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"
-        android:largeHeap="true"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity