Ensure GL initialization only happens once, and provide common init path

content/gpu/gpu_main.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.
 
 #include <stdlib.h>
 
 #if defined(OS_WIN)
 #include <dwmapi.h>
 #include <windows.h>
 #endif
@@ skipping 201 matching lines @@
     // On Chrome OS ARM, GPU driver userspace creates threads when initializing
     // a GL context, so start the sandbox early.
     gpu_info.sandboxed = StartSandboxLinux(gpu_info, watchdog_thread.get(),
                                            should_initialize_gl_context);
     initialized_sandbox = true;
 #endif
 #endif  // defined(OS_LINUX)
 
     base::TimeTicks before_initialize_one_off = base::TimeTicks::Now();
 
+    // Determine if we need to initialize GL here or it has already been done.
+    bool gl_already_initialized = false;
+#if defined(OS_MACOSX)
+    // On Mac, GLSurface::InitializeOneOff() is called from the sandbox warmup
+    // code before getting here.
+    gl_already_initialized = true;
+#endif
+    if (command_line.HasSwitch(switches::kInProcessGPU)) {
+      // With in-process GPU, GLSurface::InitializeOneOff() is called from
+      // GpuChildThread before getting here.
+      gl_already_initialized = true;
+    }
+
     // Load and initialize the GL implementation and locate the GL entry points.
-    if (gfx::GLSurface::InitializeOneOff()) {
+    bool gl_initialized =
+        gl_already_initialized
+            ? gfx::GetGLImplementation() != gfx::kGLImplementationNone
+            : gfx::GLSurface::InitializeOneOff();
+    if (gl_initialized) {
       // We need to collect GL strings (VENDOR, RENDERER) for blacklisting
       // purposes. However, on Mac we don't actually use them. As documented in
       // crbug.com/222934, due to some driver issues, glGetString could take
       // multiple seconds to finish, which in turn cause the GPU process to
       // crash.
       // By skipping the following code on Mac, we don't really lose anything,
       // because the basic GPU information is passed down from browser process
       // and we already registered them through SetGpuInfo() above.
       base::TimeTicks before_collect_context_graphics_info =
           base::TimeTicks::Now();
@@ skipping 194 matching lines @@
     return true;
   }
 
   return false;
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace.
 
 }  // namespace content