cc: zero/one-copy based on shared memory on IOS uses GL_TEXTURE_2D, not GL_TEXTURE_RECTANGLE_ARB.

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright (c) 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 1019 matching lines @@
 
   if (BrowserGpuChannelHostFactory::IsGpuMemoryBufferFactoryUsageEnabled(
           gfx::GpuMemoryBuffer::MAP)) {
     std::vector<gfx::GpuMemoryBufferType> supported_types;
     GpuMemoryBufferFactory::GetSupportedTypes(&supported_types);
     DCHECK(!supported_types.empty());
 
     // The GPU service will always use the preferred type.
     gfx::GpuMemoryBufferType type = supported_types[0];
 
-    // Surface texture backed GPU memory buffers require TEXTURE_EXTERNAL_OES.
-    if (type == gfx::SURFACE_TEXTURE_BUFFER)
-      command_line->AppendSwitch(switches::kUseImageExternal);
+    switch (type) {
+      case gfx::SURFACE_TEXTURE_BUFFER:
+        // Surface texture backed GPU memory buffers require
+        // TEXTURE_EXTERNAL_OES.
+        command_line->AppendSwitchASCII(switches::kUseImageTextureTarget,
+                                        "external");

[piman, 2014/12/03 21:16:50]

nit: can you make "external" and "rectangle" a global constant (maybe in the
content_switches.cc/h files)? Since they're used in 2 places, that gives us a
compile-time guarantee against typos.

[dshwang, 2014/12/04 09:21:14]

That's good idea. Done.
in content_switches.cc
// Texture backed image requires GL_TEXTURE_RECTANGLE_ARB target.
const char kImageTextureRectangle[] = "image-texture-rectangle";

// Texture backed image requires GL_TEXTURE_EXTERNAL_OES target.
const char kImageTextureExternal[] = "image-texture-external";

+        break;
+      case gfx::IO_SURFACE_BUFFER:
+        // IOSurface backed images require GL_TEXTURE_RECTANGLE_ARB.
+        command_line->AppendSwitchASCII(switches::kUseImageTextureTarget,
+                                        "rectangle");
+        break;
+      default:
+        break;
+    }
   }
 
   // Appending disable-gpu-feature switches due to software rendering list.
   GpuDataManagerImpl* gpu_data_manager = GpuDataManagerImpl::GetInstance();
   DCHECK(gpu_data_manager);
   gpu_data_manager->AppendRendererCommandLine(command_line);
 }
 
 void RenderProcessHostImpl::AppendRendererCommandLine(
     base::CommandLine* command_line) const {
@@ skipping 1227 matching lines @@
 
 void RenderProcessHostImpl::DecrementWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK_GT(worker_ref_count_, 0);
   --worker_ref_count_;
   if (worker_ref_count_ == 0)
     Cleanup();
 }
 
 }  // namespace content