Create correct GLES3 context for GLES3 unittest

gpu/command_buffer/service/texture_manager_unittest.cc

Index: gpu/command_buffer/service/texture_manager_unittest.cc
diff --git a/gpu/command_buffer/service/texture_manager_unittest.cc b/gpu/command_buffer/service/texture_manager_unittest.cc
index 476222672ace590cd35e28cf16dc94b3de0515ff..42941f0bb73f4daf0114baf22b7ac2ef984976b2 100644
--- a/gpu/command_buffer/service/texture_manager_unittest.cc
+++ b/gpu/command_buffer/service/texture_manager_unittest.cc
@@ -110,8 +110,12 @@ class TextureManagerTest : public GpuServiceTest {
                         bool enable_es3) {
     TestHelper::SetupFeatureInfoInitExpectationsWithGLVersion(
         gl_.get(), gl_extensions, "", gl_version,
-        feature_info_->context_type(), enable_es3);
-    feature_info_->InitializeForTesting();
+        enable_es3 ? CONTEXT_TYPE_OPENGLES3 : feature_info_->context_type(),

[Zhenyao Mo, 2016/10/21 17:51:20]

This is really messy.  I think the right fix is to change
FeatureInfo::InitializeBasicState(), and if kEnableUnsafeES3APIs is passed in,
we always set feature_info_->context_type_ to ES3, so here we don't even need
the enable_es3 arg.

[qiankun, 2016/10/22 11:47:13]

We may want to create ES2 context even the ES3 apis are enabled. So, can we set
default context type as ES3?

[Zhenyao Mo, 2016/10/25 22:41:14]

I don't think we want to change test behaviors. We might dramatically change the
test coverage and ES2 is still critical because except WebGL2, everything else
(compositing, rasterization, etc) all runs on ES3.

[qiankun, 2016/10/25 23:08:13]

So, according your last comments we cannot do this change. Keep setting context
type in test when needed.

[Zhenyao Mo, 2016/10/26 00:41:06]

The inconsistency between FeatureInfo::context_type() and enable_es3 is really
nasty and confusing. Totally not your fault, but my concern is this change makes
it even worse.  That's why I suggest if we wanna clean this, we clean it up from
the root.  Adding more hacks will create a debt to pay in the near future.

[qiankun, 2016/10/28 14:31:21]

Featureinfo has a default context_type which is set at construction time.
SetupFeatureInfo() is used to make FeatureInfo::context_type() be consistent
with which context we want to use for current test. We always have to set which
context_type (es2 or es3) will be used at the beginning of each testing. I think
it's clear here. Maybe I should change "enable_es3 ? CONTEXT_TYPE_OPENGLES3 :
feature_info_->context_type()" to "enable_es3 ? CONTEXT_TYPE_OPENGLES3 :
CONTEXT_TYPE_OPENGLES2". The similar logic is still required after remove
enable-unsafe-es3-apis flag, see yunchao's CL:
https://codereview.chromium.org/2444813002. 

[yunchao, 2016/10/31 15:18:05]

The original code is not correct, but the real fix depends on 'unsafe' mode
removal. And the same issue occur in other tests too, not only this one. 
As I have said in crbug/654787, when you run gpu_unittest with
--enable-unsafe-es3-apis, you will found many failures. All of these failures
are caused by the same reason. 

As zhenyao said, this fix is not good. Because we only need one parameter,
either the 'context_type' or the 'enable_es3'. But again, it will work only if
'unsafe' mode is removed. 

I have a local fix for all of these failures, it works if
https://codereview.chromium.org/2444813002 or a similar patch is landed (after
'unsafe' mode is removed).

[qiankun, 2016/10/31 15:51:53]

In this CL, I fixed some ES3 testing for texture manager which blocks fix of
conformance2/textures/misc/tex-image-with-bad-args.html. For current command
buffer code base, I didn't find a good solution and don't intend to fix all
failures related to enable-unsafe-es3-apis removal here. And even after removing
enable-unsafe-es3-apis, I see you still need to initialize feature_info
according context type. I think it's easy to apply the same fix here as other
places when removing unsafe mode.

+        enable_es3);
+    if (enable_es3)
+      feature_info_->InitializeForTesting(CONTEXT_TYPE_OPENGLES3);
+    else
+      feature_info_->InitializeForTesting();
     if (enable_es3) {
       EXPECT_CALL(*gl_, GetIntegerv(GL_MAX_COLOR_ATTACHMENTS, _))
           .WillOnce(SetArgPointee<1>(8))