Allow one-copy task tile worker pool to use compressed textures.

cc/resources/resource_provider.cc

Index: cc/resources/resource_provider.cc
diff --git a/cc/resources/resource_provider.cc b/cc/resources/resource_provider.cc
index 506d1d97954cd14f49c1a8422c5987a6519288c3..a50ad72c203bf560bf809c3080075233be2ced3f 100644
--- a/cc/resources/resource_provider.cc
+++ b/cc/resources/resource_provider.cc
@@ -368,6 +368,29 @@ ResourceProvider::~ResourceProvider() {
   gl->Finish();
 }
 
+bool ResourceProvider::IsResourceFormatSupported(ResourceFormat format) const {
+  const ContextProvider::Capabilities& caps =
+      output_surface_->context_provider()->ContextCapabilities();
+
+  switch (format) {
+    case ALPHA_8:
+    case RGBA_4444:
+    case RGBA_8888:
+    case RGB_565:
+    case LUMINANCE_8:
+      return true;
+    case BGRA_8888:
+      return caps.gpu.texture_format_bgra8888;
+    case ETC1:
+      return caps.gpu.texture_format_etc1;
+    case RED_8:
+      return caps.gpu.texture_rg;
+  }
+
+  NOTREACHED();
+  return false;
+}
+
 bool ResourceProvider::InUseByConsumer(ResourceId id) {
   Resource* resource = GetResource(id);
   return resource->lock_for_read_count > 0 || resource->exported_count > 0 ||
@@ -1067,10 +1090,10 @@ void ResourceProvider::Initialize() {
   max_texture_size_ = 0;  // Context expects cleared value.
   gl->GetIntegerv(GL_MAX_TEXTURE_SIZE, &max_texture_size_);
   best_texture_format_ =
-      PlatformColor::BestTextureFormat(use_texture_format_bgra_);
+      PlatformColor::BestSupportedTextureFormat(use_texture_format_bgra_);
 
-  best_render_buffer_format_ =
-      PlatformColor::BestTextureFormat(caps.gpu.render_buffer_format_bgra8888);
+  best_render_buffer_format_ = PlatformColor::BestSupportedTextureFormat(
+      caps.gpu.render_buffer_format_bgra8888);
 
   texture_id_allocator_.reset(
       new TextureIdAllocator(gl, id_allocation_chunk_size_));