cc: Adding support for RGBA_4444 tile textures

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index a80feac4ecc9f97f3fd5e731d99a43cc7ea98a99..7c8e1c7c88476d73d69eec94dce0c5aa2e6816a6 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -162,7 +162,8 @@ GLRenderer::GLRenderer(RendererClient* client,
       highp_threshold_min_(highp_threshold_min),
       highp_threshold_cache_(0),
       offscreen_context_labelled_(false),
-      on_demand_tile_raster_resource_id_(0) {
+      on_demand_tile_raster_resource_id_(0),
+      use_16_bit_resources_(resource_provider->use_16bit_textures()) {
   DCHECK(context_);
 }
 
@@ -1704,9 +1705,20 @@ void GLRenderer::DrawPictureQuad(const DrawingFrame* frame,
   quad->picture_pile->RasterToBitmap(&canvas, quad->content_rect,
                                      quad->contents_scale, NULL);
 
+  uint8_t* bitmap_pixels = NULL;

[Sami, 2013/09/05 14:13:26]

Nit: const uint8_t*

[kaanb, 2013/09/06 02:05:54]

Done.

+  if (use_16_bit_resources_) {
+    SkBitmap bitmap_16;

[enne (OOO), 2013/09/05 02:01:19]

This should probably be a member along with on_demand_tile_raster_bitmap_.  I
suspect the goal of making it a member is to not have to reallocate the buffer
if it ends up being the same size.

[Sami, 2013/09/05 14:13:26]

Furthermore, since bitmap_16 is on the stack, bitmap_pixels will point to free'd
memory as soon as we leave this block. Maybe that explains the corruption you
were seeing.

[kaanb, 2013/09/06 02:05:54]

Done.

[kaanb, 2013/09/06 02:05:54]

Great point. The overscroll glow is fixed now.

+    on_demand_tile_raster_bitmap_.copyTo(
+        &bitmap_16, SkBitmap::kARGB_4444_Config);
+    bitmap_pixels = reinterpret_cast<uint8_t*>(bitmap_16.getPixels());
+  } else {
+    bitmap_pixels = reinterpret_cast<uint8_t*>(
+        on_demand_tile_raster_bitmap_.getPixels());
+  }
+
   resource_provider_->SetPixels(
       on_demand_tile_raster_resource_id_,
-      reinterpret_cast<uint8_t*>(on_demand_tile_raster_bitmap_.getPixels()),
+      bitmap_pixels,
       gfx::Rect(quad->texture_size),
       gfx::Rect(quad->texture_size),
       gfx::Vector2d());