adds WARP support to Chromium, for Metro mode only, on Windows 8

chrome/app/chrome_main.cc

Index: chrome/app/chrome_main.cc
diff --git a/chrome/app/chrome_main.cc b/chrome/app/chrome_main.cc
index 80cd0fb2f8944215f40ee84c89adb23b886750cc..91c6161c1abb5e0a3dbf1dd869ce6664e22f0cad 100644
--- a/chrome/app/chrome_main.cc
+++ b/chrome/app/chrome_main.cc
@@ -7,9 +7,12 @@
 #include "content/public/app/content_main.h"
 
 #if defined(OS_WIN)
+#include "base/command_line.h"
 #include "base/debug/dump_without_crashing.h"
 #include "base/win/win_util.h"
 #include "chrome/common/chrome_constants.h"
+#include "chrome/common/chrome_switches.h"
+#include "gpu/config/gpu_info_collector.h"
 
 #define DLLEXPORT __declspec(dllexport)
 
@@ -49,6 +52,11 @@ int ChromeMain(int argc, const char** argv) {
       ::GetProcAddress(::GetModuleHandle(chrome::kBrowserProcessExecutableName),
           "DumpProcessWithoutCrash"));
   base::debug::SetDumpWithoutCrashingFunction(DumpProcess);
+
+  if (CommandLine::InitializedForCurrentProcess()) {
+    gpu::SetShouldFallbackToWarp(
+        CommandLine::ForCurrentProcess()->HasSwitch(switches::kViewerConnect));

[Zhenyao Mo, 2014/08/29 18:28:50]

It seems to me that we add ShouldFallbackToWarp() and SetShouldFallbackToWarp()
in an awkward place rather than gpu_data_manager, simply because the
kViewerConnect lives in chrome, not content.

Is it better to move this switch to the content side?  So the
ShoudFallbackToWarp can have a more natural implementation?

[luken, 2014/08/29 23:34:03]

I moved it. Since kViewerConnect needs to be used by delegate_execute the best
place I could find was ui_base_switches.

+  }
 #else
   params.argc = argc;
   params.argv = argv;