Cache auxiliary bitmap across draw frames

android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java

Index: android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java
diff --git a/android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java b/android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java
index d4e79c82254e6fd7d9471c49156913afbf9f2f78..0e18bbd43c4f8ebea8c72c5171411c7e8b049353 100644
--- a/android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java
+++ b/android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java
@@ -12,18 +12,30 @@ import android.graphics.Picture;
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 
+import java.lang.ref.SoftReference;
+
 /**
  * Provides auxiliary methods related to Picture objects and native SkPictures.
  */
 @JNINamespace("android_webview")
 public class JavaBrowserViewRendererHelper {
 
+    private static SoftReference<Bitmap> sCachedBitmap;
+
     /**
      * Provides a Bitmap object with a given width and height used for auxiliary rasterization.
      */
     @CalledByNative
-    private static Bitmap createBitmap(int width, int height) {
-        return Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+    private static Bitmap createBitmap(int width, int height, boolean cacheResult) {
+        if (cacheResult && sCachedBitmap != null) {
+            Bitmap result = sCachedBitmap.get();
+            if (result != null && result.getWidth() == width && result.getHeight() == height) {
+                return result;
+            }
+        }
+        Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        if (cacheResult) sCachedBitmap = new SoftReference<Bitmap>(result);

[kaanb, 2013/05/23 16:56:11]

nit: it would be more readable if you break this statement into two lines.

[joth, 2013/05/23 20:23:14]

Done.

+        return result;
     }
 
     /**