cc: Avoid extra flush calls to Skia GrContext

cc/resources/resource_provider.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/resource_provider.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 971 matching lines @@
       resource_provider_->GrContext(use_worker_context);
   uint32_t flags =
       use_distance_field_text ? SkSurfaceProps::kUseDistanceFieldFonts_Flag : 0;
   // Use unknown pixel geometry to disable LCD text.
   SkSurfaceProps surface_props(flags, kUnknown_SkPixelGeometry);
   if (can_use_lcd_text) {
     // LegacyFontHost will get LCD text and skia figures out what type to use.
     surface_props =
         SkSurfaceProps(flags, SkSurfaceProps::kLegacyFontHost_InitType);
   }
-  sk_surface_ = skia::AdoptRef(
-      SkSurface::NewWrappedRenderTarget(gr_context, desc, &surface_props));
+  gr_surface_ =

[bsalomon, 2016/02/09 14:55:56]

Why this change? Is there something missing from the NewWrappedRenderTarget API
that is available via wrapBackendTexture()? I'd like to eventually make all
external textures and FBOs be imported via SkSurface and SkImage APIs and remove
the methods from GrTextureProvider.

[Kimmo Kinnunen, 2016/02/09 18:13:44]

To get a GrSurface reference. Maybe I'm missing an accessor that is there?

[bsalomon, 2016/02/09 18:22:12]

Oh, of course.

+      skia::AdoptRef(gr_context->textureProvider()->wrapBackendTexture(
+          desc, kBorrow_GrWrapOwnership));
+  if (gr_surface_)
+    sk_surface_ = skia::AdoptRef(SkSurface::NewRenderTargetDirect(
+        gr_surface_->asRenderTarget(), &surface_props));
 }
 
 void ResourceProvider::ScopedWriteLockGr::ReleaseSkSurface() {
+  DCHECK(gr_surface_);
+  gr_surface_->prepareForExternalIO();

[Kimmo Kinnunen, 2016/02/09 18:13:44]

For this call, we need GrSurface.

[Kimmo Kinnunen, 2016/02/09 18:17:27]

Or are you hinting it'd be better just call sk_surface->getCanvas()->flush(); ?

[bsalomon, 2016/02/09 18:22:12]

I think that'd be preferable. I had been thinking that flush() should probably
be moved to SkSurface and perhaps renamed. If that would make this more readable
I'm happy to land a CL in Skia.

+  gr_surface_.clear();
   sk_surface_.clear();
 }
 
 ResourceProvider::SynchronousFence::SynchronousFence(
     gpu::gles2::GLES2Interface* gl)
     : gl_(gl), has_synchronized_(true) {
 }
 
 ResourceProvider::SynchronousFence::~SynchronousFence() {
 }
@@ skipping 773 matching lines @@
 
     const int kImportance = 2;
     pmd->CreateSharedGlobalAllocatorDump(guid);
     pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
   }
 
   return true;
 }
 
 }  // namespace cc