Refactor more Texture entry points to a consistent style.

TexImage, SubImage and the Compressed variants were all taking a GL
Context as the first parameter, which is a layering violation and
also caused problems with reworking how the sync works. Fix this
by refactoring them in the same style as the CopyTex* entry points.

BUG=angleproject:1260
BUG=angleproject:747

Change-Id: Ibe5e87d0ebc790e2dcadb8ba153cf40fec73d1f6
Reviewed-on: https://chromium-review.googlesource.com/327258
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/Image_unittest.cpp b/src/libANGLE/Image_unittest.cpp
index c9de26f..9c89be0 100644
--- a/src/libANGLE/Image_unittest.cpp
+++ b/src/libANGLE/Image_unittest.cpp
@@ -87,10 +87,12 @@
     gl::Texture *texture = new gl::Texture(textureImpl, 1, GL_TEXTURE_2D);
     texture->addRef();
 
+    gl::PixelUnpackState defaultUnpackState;
+
     EXPECT_CALL(*textureImpl, setImage(_, _, _, _, _, _, _, _))
         .WillOnce(Return(gl::Error(GL_NO_ERROR)))
         .RetiresOnSaturation();
-    texture->setImage(nullptr, GL_TEXTURE_2D, 0, GL_RGBA8, gl::Extents(1, 1, 1), GL_RGBA,
+    texture->setImage(defaultUnpackState, GL_TEXTURE_2D, 0, GL_RGBA8, gl::Extents(1, 1, 1), GL_RGBA,
                       GL_UNSIGNED_BYTE, nullptr);
 
     rx::MockImageImpl *imageImpl = new rx::MockImageImpl();
@@ -110,7 +112,7 @@
         .WillOnce(Return(gl::Error(GL_NO_ERROR)))
         .RetiresOnSaturation();
 
-    texture->setImage(nullptr, GL_TEXTURE_2D, 0, GL_RGBA8, gl::Extents(1, 1, 1), GL_RGBA,
+    texture->setImage(defaultUnpackState, GL_TEXTURE_2D, 0, GL_RGBA8, gl::Extents(1, 1, 1), GL_RGBA,
                       GL_UNSIGNED_BYTE, nullptr);
 
     EXPECT_EQ(texture->getRefCount(), 1u);