Remaining code for basic tile compression functionality.

cc/raster/tile_task_worker_pool.cc

Index: cc/raster/tile_task_worker_pool.cc
diff --git a/cc/raster/tile_task_worker_pool.cc b/cc/raster/tile_task_worker_pool.cc
index d349514c4e84ceba7d91cbf997c7e5c320cc2c84..0a2b18f31da4ffaaaf1cc0b9038209f3124f5b54 100644
--- a/cc/raster/tile_task_worker_pool.cc
+++ b/cc/raster/tile_task_worker_pool.cc
@@ -8,6 +8,7 @@
 
 #include "base/trace_event/trace_event.h"
 #include "cc/playback/raster_source.h"
+#include "cc/raster/texture_compressor.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkSurface.h"
@@ -141,11 +142,11 @@ static bool IsSupportedPlaybackToMemoryFormat(ResourceFormat format) {
     case RGBA_4444:
     case RGBA_8888:
     case BGRA_8888:
+    case ETC1:
       return true;
     case ALPHA_8:
     case LUMINANCE_8:
     case RGB_565:
-    case ETC1:
     case RED_8:
       return false;
   }
@@ -167,8 +168,8 @@ void TileTaskWorkerPool::PlaybackToMemory(void* memory,
   // Uses kPremul_SkAlphaType since the result is not known to be opaque.
   SkImageInfo info =
       SkImageInfo::MakeN32(size.width(), size.height(), kPremul_SkAlphaType);
-  SkColorType buffer_color_type = ResourceFormatToSkColorType(format);
-  bool needs_copy = buffer_color_type != info.colorType();
+  bool needs_copy = IsResourceFormatCompressed(format) ||

[reveman, 2015/07/21 04:26:33]

nit: s/needs_copy/needs_conversion/

The only format that doesn't need conversion is info.colorType(). Instead of
adding a special case for IsResourceFormatCompressed, can we simply get the
matching resource format for info.colorType() and set needs_conversion to true
if it doesn't match |format|?

+                    ResourceFormatToSkColorType(format) != info.colorType();
 
   // Use unknown pixel geometry to disable LCD text.
   SkSurfaceProps surface_props(0, kUnknown_SkPixelGeometry);
@@ -196,16 +197,30 @@ void TileTaskWorkerPool::PlaybackToMemory(void* memory,
   raster_source->PlaybackToCanvas(canvas.get(), canvas_bitmap_rect,
                                   canvas_playback_rect, scale);
 
-  SkImageInfo dst_info =
-      SkImageInfo::Make(info.width(), info.height(), buffer_color_type,
-                        info.alphaType(), info.profileType());
-  // TODO(kaanb): The GL pipeline assumes a 4-byte alignment for the
-  // bitmap data. There will be no need to call SkAlign4 once crbug.com/293728
-  // is fixed.
-  const size_t dst_row_bytes = SkAlign4(dst_info.minRowBytes());
-  DCHECK_EQ(0u, dst_row_bytes % 4);
-  bool success = canvas->readPixels(dst_info, memory, dst_row_bytes, 0, 0);
-  DCHECK_EQ(true, success);
+  scoped_ptr<TextureCompressor> texture_compressor;
+  switch (format) {
+    case ETC1:
+      texture_compressor =
+          TextureCompressor::Create(TextureCompressor::kFormatETC1);

[reveman, 2015/07/21 04:26:33]

hm, I think we should assume that creating a texture compressor instance is
expensive. can we use a process wide instance?

+      break;
+    default:

[reveman, 2015/07/21 04:26:33]

Please explicitly list all formats here and add a NOTREACHED below instead of a
default case. Makes it easy to see that this code needs to be updated when
adding a new format.

+      SkImageInfo dst_info = SkImageInfo::Make(
+          info.width(), info.height(), ResourceFormatToSkColorType(format),
+          info.alphaType(), info.profileType());
+      // TODO(kaanb): The GL pipeline assumes a 4-byte alignment for the
+      // bitmap data. There will be no need to call SkAlign4 once
+      // crbug.com/293728 is fixed.
+      const size_t dst_row_bytes = SkAlign4(dst_info.minRowBytes());
+      DCHECK_EQ(0u, dst_row_bytes % 4);
+      bool success = canvas->readPixels(dst_info, memory, dst_row_bytes, 0, 0);
+      DCHECK_EQ(true, success);
+      return;
+  }
+
+  texture_compressor->Compress(
+      reinterpret_cast<const uint8_t*>(surface->peekPixels(nullptr, nullptr)),
+      reinterpret_cast<uint8_t*>(memory), size.width(), size.height(),
+      TextureCompressor::kQualityHigh);
 }
 
 }  // namespace cc