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

ui/gl/gl_surface.cc

Index: ui/gl/gl_surface.cc
diff --git a/ui/gl/gl_surface.cc b/ui/gl/gl_surface.cc
index a52a3f7110f3e7eea942f4597e6a38237e51556a..5179811bfaf470cd218042751aace9597b71fa94 100644
--- a/ui/gl/gl_surface.cc
+++ b/ui/gl/gl_surface.cc
@@ -14,6 +14,7 @@
 #include "base/threading/thread_local.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_switches.h"
 
 namespace gfx {
 
@@ -24,9 +25,7 @@ base::LazyInstance<base::ThreadLocalPointer<GLSurface> >::Leaky
 
 // static
 bool GLSurface::InitializeOneOff() {
-  static bool initialized = false;
-  if (initialized)
-    return true;
+  DCHECK_EQ(kGLImplementationNone, GetGLImplementation());
 
   TRACE_EVENT0("gpu", "GLSurface::InitializeOneOff");
 
@@ -44,6 +43,8 @@ bool GLSurface::InitializeOneOff() {
       fallback_to_osmesa = true;
     } else if (requested_implementation_name == "swiftshader") {
       impl = kGLImplementationEGLGLES2;
+    } else if (requested_implementation_name == kGLImplementationMockName) {
+      impl = kGLImplementationMockGL;
     } else {
       impl = GetNamedGLImplementation(requested_implementation_name);
       if (std::find(allowed_impls.begin(),
@@ -55,12 +56,15 @@ bool GLSurface::InitializeOneOff() {
     }
   }
 
-  initialized = InitializeStaticGLBindings(impl) && InitializeOneOffInternal();
+  bool initialized =
+      InitializeStaticGLBindings(impl) && InitializeOneOffInternal();
   if (!initialized && fallback_to_osmesa) {
     ClearGLBindings();
     initialized = InitializeStaticGLBindings(kGLImplementationOSMesaGL) &&
                   InitializeOneOffInternal();
   }
+  if (!initialized)
+    ClearGLBindings();
 
   if (initialized) {
     DVLOG(1) << "Using "
@@ -76,6 +80,56 @@ bool GLSurface::InitializeOneOff() {
   return initialized;
 }
 
+// static
+void GLSurface::InitializeOneOffForTests() {
+  CommandLine* cmd = CommandLine::ForCurrentProcess();
+
+  bool use_osmesa = true;
+
+#if defined(OS_ANDROID)
+  // On Android we always use hardware GL.
+  use_osmesa = false;
+#endif
+
+  if (use_osmesa) {
+    if (cmd->HasSwitch(switches::kUseGL)) {
+      DCHECK(cmd->GetSwitchValueASCII(switches::kUseGL) ==

[piman, 2014/01/24 19:22:23]

nit: maybe CHECK with an error message, so that naughty users that try to pass
--use-gl get a warning?

[danakj, 2014/01/24 20:17:23]

kk

+             kGLImplementationOSMesaName);
+    } else {
+      cmd->AppendSwitchASCII(switches::kUseGL, kGLImplementationOSMesaName);
+    }
+  } else {
+    DCHECK(!cmd->HasSwitch(switches::kUseGL));
+  }
+
+  // TODO(danakj): Unit tests do not produce pixel output by default.
+  // cmd->AppendSwitch(switches::kDisableGLDrawingForTests);
+
+  CHECK(InitializeOneOff());
+}
+
+// static
+void GLSurface::InitializeOneOffWithMockBindingsForTests() {
+  CommandLine* cmd = CommandLine::ForCurrentProcess();
+  if (cmd->HasSwitch(switches::kUseGL)) {
+    DCHECK(cmd->GetSwitchValueASCII(switches::kUseGL) ==
+           kGLImplementationMockName);
+  } else {
+    cmd->AppendSwitchASCII(switches::kUseGL, kGLImplementationMockName);
+  }
+
+  // This method may be called multiple times in the same process to set up
+  // mock bindings in different ways.
+  ClearGLBindings();
+
+  CHECK(InitializeOneOff());
+}
+
+// static
+void GLSurface::InitializeDynamicMockBindingsForTests(GLContext* context) {
+  CHECK(InitializeDynamicGLBindings(kGLImplementationMockGL, context));
+}
+
 GLSurface::GLSurface() {}
 
 bool GLSurface::Initialize() {