gpu: Completely remove GpuProcessHostUIShim.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 0dc52fcaf88e98e2dcf3b4a4858b357f8210f0ad..a98d473909cd25dc15d6e3ac7cdc5bda2f40d8e2 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -61,7 +61,6 @@
 #include "content/browser/gpu/compositor_util.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
 #include "content/browser/gpu/gpu_process_host.h"
-#include "content/browser/gpu/gpu_process_host_ui_shim.h"
 #include "content/browser/gpu/shader_cache_factory.h"
 #include "content/browser/histogram_synchronizer.h"
 #include "content/browser/leveldb_wrapper_impl.h"
@@ -119,6 +118,11 @@
 #include "ui/aura/env.h"
 #endif
 
+#if defined(USE_OZONE)
+#include "ui/ozone/public/gpu_platform_support_host.h"
+#include "ui/ozone/public/ozone_platform.h"
+#endif
+
 #if defined(OS_ANDROID)
 #include "base/android/jni_android.h"
 #include "components/tracing/common/graphics_memory_dump_provider_android.h"
@@ -646,6 +650,15 @@ void BrowserMainLoop::MainMessageLoopStart() {
     main_message_loop_.reset(new base::MessageLoopForUI);
 
   InitializeMainThread();
+#if defined(USE_OZONE)
+  DCHECK(env_);
+  if (env_->mode() == aura::Env::Mode::LOCAL) {
+    DCHECK(ui::OzonePlatform::GetInstance());
+    ui::OzonePlatform::GetInstance()
+        ->GetGpuPlatformSupportHost()
+        ->BindToCurrentThread();

[jam, 2017/04/20 00:22:20]

why not just pass in the UI thread's task runner in OnGpuProcessLaunched, and
then you don't need to add more code to this file?

[sadrul, 2017/04/20 03:10:31]

Yep, that also works. Done.

+  }
+#endif
 }
 
 void BrowserMainLoop::PostMainMessageLoopStart() {