Cache auxiliary bitmap across draw frames

android_webview/browser/browser_view_renderer_impl.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "android_webview/browser/browser_view_renderer_impl.h"
 
 #include <android/bitmap.h>
 
 #include "android_webview/browser/in_process_renderer/in_process_view_renderer.h"
 #include "android_webview/common/aw_switches.h"
@@ skipping 324 matching lines @@
   if (clip.IsEmpty())
     return true;
 
   AwPixelInfo* pixels;
   JNIEnv* env = AttachCurrentThread();
 
   // Render into an auxiliary bitmap if pixel info is not available.
   if (!g_sw_draw_functions ||
       (pixels = g_sw_draw_functions->access_pixels(env, java_canvas)) == NULL) {
     ScopedJavaLocalRef<jobject> jbitmap(java_helper_->CreateBitmap(
-        env, clip.width(), clip.height()));
+        env, clip.width(), clip.height(), true));
     if (!jbitmap.obj())
       return false;
 
     if (!RasterizeIntoBitmap(env, jbitmap, clip.x(), clip.y(),
                              base::Bind(&BrowserViewRendererImpl::RenderSW,
                                         base::Unretained(this)))) {
       return false;
     }
 
     ScopedJavaLocalRef<jobject> jcanvas(env, java_canvas);
@@ skipping 57 matching lines @@
   if (g_is_skia_version_compatible) {
     // Add a reference that the create_picture() will take ownership of.
     picture->ref();
     return ScopedJavaLocalRef<jobject>(env,
         g_sw_draw_functions->create_picture(env, picture.get()));
   }
 
   // If Skia versions are not compatible, workaround it by rasterizing the
   // picture into a bitmap and drawing it into a new Java picture.
   ScopedJavaLocalRef<jobject> jbitmap(java_helper_->CreateBitmap(
-      env, picture->width(), picture->height()));
+      env, picture->width(), picture->height(), false));

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

Any reason we don't want to support it for CapturePicture?

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

(this whole file is being deleted soon, but for the other version of this...)
The SkPicture has a shallow ref to any bitmaps drawn, but the client may hold
onto the picture for a long time. so if we reuse the bitmap for different
purposes, we'll corrupt previously drawn pictures.
Added a comment to the other place to explain this.

   if (!jbitmap.obj())
     return ScopedJavaLocalRef<jobject>();
 
   if (!RasterizeIntoBitmap(env, jbitmap, 0, 0,
       base::Bind(&RenderPictureToCanvas,
                  base::Unretained(picture.get())))) {
     return ScopedJavaLocalRef<jobject>();
   }
 
   return java_helper_->RecordBitmapIntoPicture(env, jbitmap);
@@ skipping 127 matching lines @@
 
 void BrowserViewRendererImpl::OnFrameInfoUpdated(
     const gfx::SizeF& content_size,
     const gfx::Vector2dF& scroll_offset,
     float page_scale_factor) {
   page_scale_ = page_scale_factor;
   content_size_css_ = content_size;
 }
 
 }  // namespace android_webview