chromeos: Fix pixelated icons in app list and launcher (part 1)

ui/app_list/icon_cache.cc

Index: ui/app_list/icon_cache.cc
diff --git a/ui/app_list/icon_cache.cc b/ui/app_list/icon_cache.cc
index b0b9997e6aebc9113232521827a3a0c956fc6e43..b684b88aad5f25e7b89fd3161f18d64374e65f90 100644
--- a/ui/app_list/icon_cache.cc
+++ b/ui/app_list/icon_cache.cc
@@ -11,10 +11,11 @@
 namespace {
 
 // Gets cache key based on |image| contents and desired |size|.
-std::string GetKey(const SkBitmap& image, const gfx::Size& size) {
-  SkAutoLockPixels image_lock(image);
+std::string GetKey(const gfx::ImageSkia& image, const gfx::Size& size) {
+  const SkBitmap* bitmap = image.bitmap();

[pkotwicz, 2012/07/04 00:19:50]

I think you should call GetRepresentation(ui::SCALE_FACTOR_100P) to kick the
lazy loading via ImageSkiaSource.
This avoids having to call image.GetRepresentation(...) in
ResizeAndGenerateShadow()
Still take the MD5 sum from image.bitmap() though.
The reason is that bitmap() will always return the same bitmap even if the
ImageSkia changes, barring deleting an entry while GetRepresentation will not.
This is a hack. Please put a TODO for me or Oshima to fix this.

[xiyuan, 2012/07/10 20:02:13]

We will have to call GetRepresentation in ResizeAndGenerateShadow to actually
generate the image. ResizeAndGenerateShadow runs a background worker thread and
the purpose of having it is to generate the resize and shadowed image out of UI
thread. And IconCache is used to cache the result so that we don't need to
calculate it again. Lazing loading etc does not make much sense in this scenario
and think we want to get the same key for the same bitmap here.

[pkotwicz, 2012/07/11 00:12:44]

I understand now. The code as you have written is correct.

+  SkAutoLockPixels image_lock(*bitmap);
   base::MD5Digest digest;
-  MD5Sum(image.getPixels(), image.getSize(), &digest);
+  MD5Sum(bitmap->getPixels(), bitmap->getSize(), &digest);
 
   return MD5DigestToBase16(digest) + "." + size.ToString();
 }
@@ -59,9 +60,9 @@ void IconCache::PurgeAllUnused() {
   }
 }
 
-bool IconCache::Get(const SkBitmap& src,
+bool IconCache::Get(const gfx::ImageSkia& src,
                     const gfx::Size& size,
-                    SkBitmap* processed) {
+                    gfx::ImageSkia* processed) {
   Cache::iterator it = cache_.find(GetKey(src, size));
   if (it == cache_.end())
     return false;
@@ -73,9 +74,9 @@ bool IconCache::Get(const SkBitmap& src,
   return true;
 }
 
-void IconCache::Put(const SkBitmap& src,
+void IconCache::Put(const gfx::ImageSkia& src,
                     const gfx::Size& size,
-                    const SkBitmap& processed) {
+                    const gfx::ImageSkia& processed) {
   const std::string key = GetKey(src, size);
   cache_[key].image = processed;
   cache_[key].used = true;