cc: Adding support for RGBA_4444 tile textures

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 773a689ac03749590685580a88dafb9cb92fcf0b..122549175c8baf04ff66bf8c45554c4436a52349 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -29,6 +29,7 @@
 #include "cc/layers/painted_scrollbar_layer.h"
 #include "cc/layers/render_surface.h"
 #include "cc/resources/prioritized_resource_manager.h"
+#include "cc/resources/resource_provider.h"
 #include "cc/resources/ui_resource_client.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_common.h"
@@ -47,7 +48,7 @@ static int s_num_layer_tree_instances;
 namespace cc {
 
 RendererCapabilities::RendererCapabilities()
-    : best_texture_format(0),
+    : best_texture_format(ResourceProvider::RGBA_8888),
       using_partial_swap(false),
       using_set_visibility(false),
       using_egl_image(false),
@@ -197,7 +198,8 @@ LayerTreeHost::OnCreateAndInitializeOutputSurfaceAttempted(bool success) {
       contents_texture_manager_ =
           PrioritizedResourceManager::Create(proxy_.get());
       surface_memory_placeholder_ =
-          contents_texture_manager_->CreateTexture(gfx::Size(), GL_RGBA);
+          contents_texture_manager_->CreateTexture(gfx::Size(),
+                                                   ResourceProvider::RGBA_8888);
     }
 
     client_->DidInitializeOutputSurface(true);
@@ -917,7 +919,7 @@ size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
 
     size_t bytes =
         Resource::MemorySizeBytes(render_surface->content_rect().size(),
-                                  GL_RGBA);
+                                  ResourceProvider::RGBA_8888);
     contents_texture_bytes += bytes;
 
     if (render_surface_layer->background_filters().IsEmpty())
@@ -927,7 +929,7 @@ size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
       max_background_texture_bytes = bytes;
     if (!readback_bytes) {
       readback_bytes = Resource::MemorySizeBytes(device_viewport_size_,
-                                                 GL_RGBA);
+                                                 ResourceProvider::RGBA_8888);
     }
   }
   return readback_bytes + max_background_texture_bytes + contents_texture_bytes;