Add PERSISTENT_MAP usage for GpuMemoryBuffers.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 194eb3596d4280acd53d7e3bebf820ff5347d170..dc81915ea222449cc4b5369a52ea2a09f81387cd 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1137,10 +1137,22 @@ static void AppendCompositorCommandLineFlags(base::CommandLine* command_line) {
   if (IsForceGpuRasterizationEnabled())
     command_line->AppendSwitch(switches::kForceGpuRasterization);
 
+  // TODO(reveman): We currently assume that the compositor will use BGRA_8888
+  // if it's able to, and RGBA_8888 otherwise. Since we don't know what it will
+  // use we hardcode BGRA_8888 here for now. We should instead
+  // move decisions about GpuMemoryBuffer format to the browser embedder so we
+  // know it here, and pass that decision to the compositor for each usage.
+  // crbug.com/490362
+  gfx::GpuMemoryBuffer::Format format = gfx::GpuMemoryBuffer::BGRA_8888;
+
+  // TODO(danakj): When one-copy uploads support partial update, change this
+  // usage to PERSISTENT_MAP for one-copy.
+  gfx::GpuMemoryBuffer::Usage usage = gfx::GpuMemoryBuffer::MAP;
+
   command_line->AppendSwitchASCII(
       switches::kUseImageTextureTarget,
       base::UintToString(
-          BrowserGpuChannelHostFactory::GetImageTextureTarget()));
+          BrowserGpuChannelHostFactory::GetImageTextureTarget(format, usage)));
 
   // Appending disable-gpu-feature switches due to software rendering list.
   GpuDataManagerImpl* gpu_data_manager = GpuDataManagerImpl::GetInstance();