pepper: parse context creation attrib list on the plugin side

ppapi/proxy/ppb_graphics_3d_proxy.cc

Index: ppapi/proxy/ppb_graphics_3d_proxy.cc
diff --git a/ppapi/proxy/ppb_graphics_3d_proxy.cc b/ppapi/proxy/ppb_graphics_3d_proxy.cc
index 0c21e377733751873561ff42642fd1df3a818fba..81df45b71ed82b2e2ba0c7fcce52dcb7cd08a2cf 100644
--- a/ppapi/proxy/ppb_graphics_3d_proxy.cc
+++ b/ppapi/proxy/ppb_graphics_3d_proxy.cc
@@ -172,24 +172,42 @@ PP_Resource PPB_Graphics3D_Proxy::CreateProxyResource(
     share_gles2 = share_graphics->gles2_impl();
   }
 
+  gpu::gles2::ContextCreationAttribHelper attrib_helper;
   std::vector<int32_t> attribs;
   if (attrib_list) {
-    for (const int32_t* attr = attrib_list;
-         attr[0] != PP_GRAPHICS3DATTRIB_NONE;
+    for (const int32_t* attr = attrib_list; attr[0] != PP_GRAPHICS3DATTRIB_NONE;
          attr += 2) {
-      attribs.push_back(attr[0]);
-      attribs.push_back(attr[1]);
+      switch (attr[0]) {
+        case PP_GRAPHICS3DATTRIB_WIDTH:
+          attrib_helper.offscreen_framebuffer_size.set_width(attr[1]);
+          break;
+        case PP_GRAPHICS3DATTRIB_HEIGHT:
+          attrib_helper.offscreen_framebuffer_size.set_height(attr[1]);
+          break;
+        case PP_GRAPHICS3DATTRIB_GPU_PREFERENCE:
+          attrib_helper.gpu_preference =
+              (attr[1] == PP_GRAPHICS3DATTRIB_GPU_PREFERENCE_LOW_POWER)
+                  ? gl::PreferIntegratedGpu
+                  : gl::PreferDiscreteGpu;
+          break;
+        default:
+          attribs.push_back(attr[0]);
+          attribs.push_back(attr[1]);
+          break;
+      }
     }
+    attribs.push_back(PP_GRAPHICS3DATTRIB_NONE);
   }
-  attribs.push_back(PP_GRAPHICS3DATTRIB_NONE);
+  if (!attrib_helper.Parse(attribs))
+    return 0;
 
   HostResource result;
   gpu::Capabilities capabilities;
   ppapi::proxy::SerializedHandle shared_state;
   gpu::CommandBufferId command_buffer_id;
-  dispatcher->Send(new PpapiHostMsg_PPBGraphics3D_Create(API_ID_PPB_GRAPHICS_3D,
-        instance, share_host, attribs, &result, &capabilities, &shared_state,
-        &command_buffer_id));
+  dispatcher->Send(new PpapiHostMsg_PPBGraphics3D_Create(
+      API_ID_PPB_GRAPHICS_3D, instance, share_host, attrib_helper, &result,
+      &capabilities, &shared_state, &command_buffer_id));
 
   if (result.is_null())
     return 0;
@@ -240,16 +258,12 @@ bool PPB_Graphics3D_Proxy::OnMessageReceived(const IPC::Message& msg) {
 void PPB_Graphics3D_Proxy::OnMsgCreate(
     PP_Instance instance,
     HostResource share_context,
-    const std::vector<int32_t>& attribs,
+    const gpu::gles2::ContextCreationAttribHelper& attrib_helper,
     HostResource* result,
     gpu::Capabilities* capabilities,
     SerializedHandle* shared_state,
     gpu::CommandBufferId* command_buffer_id) {
   shared_state->set_null_shmem();
-  if (attribs.empty() ||
-      attribs.back() != PP_GRAPHICS3DATTRIB_NONE ||
-      !(attribs.size() & 1))
-    return;  // Bad message.
 
   thunk::EnterResourceCreation enter(instance);
 
@@ -258,13 +272,9 @@ void PPB_Graphics3D_Proxy::OnMsgCreate(
 
   base::SharedMemoryHandle handle = base::SharedMemory::NULLHandle();
   result->SetHostResource(
-      instance,
-      enter.functions()->CreateGraphics3DRaw(instance,
-                                             share_context.host_resource(),
-                                             &attribs.front(),
-                                             capabilities,
-                                             &handle,
-                                             command_buffer_id));
+      instance, enter.functions()->CreateGraphics3DRaw(
+                    instance, share_context.host_resource(), attrib_helper,
+                    capabilities, &handle, command_buffer_id));
   if (!result->is_null()) {
     shared_state->set_shmem(TransportSHMHandle(dispatcher(), handle),
                             sizeof(gpu::CommandBuffer::State));