Support Re-using Bitmaps with RGBA_F16 configs.

Also adds emulator tests for wide gamut images on API 26+.

instrumentation/src/androidTest/java/com/bumptech/glide/WideGamutTest.java

@@ -0,0 +1,139 @@
+package com.bumptech.glide;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assume.assumeTrue;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.CompressFormat;
+import android.graphics.ColorSpace;
+import android.graphics.ColorSpace.Named;
+import android.os.Build;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+import com.bumptech.glide.load.DecodeFormat;
+import com.bumptech.glide.load.engine.bitmap_recycle.LruBitmapPool;
+import com.bumptech.glide.test.ConcurrencyHelper;
+import com.bumptech.glide.test.GlideApp;
+import com.bumptech.glide.test.ResourceIds;
+import com.bumptech.glide.test.TearDownGlide;
+import java.io.ByteArrayOutputStream;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TestRule;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class WideGamutTest {
+  @Rule public final TestRule tearDownGlide = new TearDownGlide();
+  private final ConcurrencyHelper concurrency = new ConcurrencyHelper();
+  private final Context context = InstrumentationRegistry.getTargetContext();
+
+  @Before
+  public void setUp() {
+    assumeTrue(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O);
+  }
+
+  @Test
+  public void load_withWideGamutImage_returnsWideGamutBitmap() {
+    Bitmap bitmap =
+        concurrency.get(
+            Glide.with(context)
+                .asBitmap()
+                .load(ResourceIds.raw.webkit_logo_p3)
+                .submit());
+    assertThat(bitmap.getConfig()).isEqualTo(Bitmap.Config.RGBA_F16);
+  }
+
+  @Test
+  public void load_withWideGamutImage_bitmapInPoolWithSizeAndConfig_usesBitmapFromPool() {
+    int bitmapDimension = 1000;
+    Glide.init(
+        context,
+        new GlideBuilder()
+            .setBitmapPool(new LruBitmapPool(bitmapDimension * bitmapDimension * 8 * 4)));
+    Bitmap expected = Bitmap.createBitmap(bitmapDimension, bitmapDimension, Bitmap.Config.RGBA_F16);
+
+    Glide.get(context)
+        .getBitmapPool()
+        .put(expected);
+
+    Bitmap bitmap =
+        concurrency.get(
+            Glide.with(context)
+                .asBitmap()
+                .load(ResourceIds.raw.webkit_logo_p3)
+                .submit());
+    assertThat(bitmap).isSameAs(expected);
+  }
+
+  @Test
+  public void load_withWideGamutImage_hardwareAllowed_returnsHardwareBitmap() {
+    Bitmap bitmap =
+        concurrency.get(
+            GlideApp.with(context)
+                .asBitmap()
+                .format(DecodeFormat.PREFER_ARGB_8888)
+                .load(ResourceIds.raw.webkit_logo_p3)
+                .submit());
+    assertThat(bitmap.getConfig()).isEqualTo(Bitmap.Config.HARDWARE);
+  }
+
+  @Test
+  public void load_withEncodedPngWideGamutImage_decodesWideGamut() {
+    Bitmap toCompress =
+        Bitmap.createBitmap(
+            100, 100, Bitmap.Config.RGBA_F16, /*hasAlpha=*/ true, ColorSpace.get(Named.DCI_P3));
+
+    ByteArrayOutputStream os = new ByteArrayOutputStream();
+    toCompress.compress(CompressFormat.PNG, 100, os);
+    byte[] data = os.toByteArray();
+
+      Bitmap bitmap =
+        concurrency.get(
+            Glide.with(context)
+                .asBitmap()
+                .load(data)
+                .submit());
+    assertThat(bitmap.getConfig()).isEqualTo(Bitmap.Config.RGBA_F16);
+  }
+
+  @Test
+  public void load_withEncodedJpegWideGamutImage_decodesArgb8888() {
+    Bitmap toCompress =
+        Bitmap.createBitmap(
+            100, 100, Bitmap.Config.RGBA_F16, /*hasAlpha=*/ true, ColorSpace.get(Named.DCI_P3));
+
+    ByteArrayOutputStream os = new ByteArrayOutputStream();
+    toCompress.compress(CompressFormat.JPEG, 100, os);
+    byte[] data = os.toByteArray();
+
+      Bitmap bitmap =
+        concurrency.get(
+            Glide.with(context)
+                .asBitmap()
+                .load(data)
+                .submit());
+    assertThat(bitmap.getConfig()).isEqualTo(Bitmap.Config.ARGB_8888);
+  }
+
+  @Test
+  public void load_withEncodedWebpWideGamutImage_decodesArgb8888() {
+    Bitmap toCompress =
+        Bitmap.createBitmap(
+            100, 100, Bitmap.Config.RGBA_F16, /*hasAlpha=*/ true, ColorSpace.get(Named.DCI_P3));
+
+    ByteArrayOutputStream os = new ByteArrayOutputStream();
+    toCompress.compress(CompressFormat.WEBP, 100, os);
+    byte[] data = os.toByteArray();
+
+      Bitmap bitmap =
+        concurrency.get(
+            Glide.with(context)
+                .asBitmap()
+                .load(data)
+                .submit());
+    assertThat(bitmap.getConfig()).isEqualTo(Bitmap.Config.ARGB_8888);
+  }
+}

instrumentation/src/androidTest/java/com/bumptech/glide/test/ResourceIds.java

@@ -20,6 +20,7 @@ public interface raw {
     int transparent_gif = getResourceId("raw", "transparent_gif");
     int opaque_gif = getResourceId("raw", "opaque_gif");
     int opaque_interlaced_gif = getResourceId("raw", "opaque_interlaced_gif");
+    int webkit_logo_p3 = getResourceId("raw", "webkit_logo_p3");
   }
 
   public interface drawable {

library/src/main/java/com/bumptech/glide/load/resource/bitmap/Downsampler.java

@@ -664,16 +664,27 @@ private static IOException newIoExceptionForInBitmapAssertion(IllegalArgumentExc
 
   @SuppressWarnings("PMD.CollapsibleIfStatements")
   @TargetApi(Build.VERSION_CODES.O)
-  private static void setInBitmap(BitmapFactory.Options options, BitmapPool bitmapPool, int width,
-      int height) {
+  private static void setInBitmap(
+      BitmapFactory.Options options, BitmapPool bitmapPool, int width, int height) {
+
+    Bitmap.Config expectedConfig;
     // Avoid short circuiting, it appears to break on some devices.
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
       if (options.inPreferredConfig == Config.HARDWARE) {
         return;
       }
+      expectedConfig = options.outConfig;
+    } else {
+      // We're going to guess that BitmapFactory will return us the config we're requesting. This
+      // isn't always the case, even though our guesses tend to be conservative and prefer configs
+      // of larger sizes so that the Bitmap will fit our image anyway. If we're wrong here and the
+      // config we choose is too small, our initial decode will fail, but we will retry with no
+      // inBitmap which will succeed so if we're wrong here, we're less efficient but still correct.
+      expectedConfig = options.inPreferredConfig;
     }
+
     // BitmapFactory will clear out the Bitmap before writing to it, so getDirty is safe.
-    options.inBitmap = bitmapPool.getDirty(width, height, options.inPreferredConfig);
+    options.inBitmap = bitmapPool.getDirty(width, height, expectedConfig);
   }
 
   private static synchronized BitmapFactory.Options getDefaultOptions() {