Revert "Optimize disabling ARB_texture_rectangle"

This reverts commit 7e9c0cd6.

Reason for revert: https://bugs.chromium.org/p/chromium/issues/detail?id=1042758

Original change's description:
> Optimize disabling ARB_texture_rectangle
> 
> In https://crrev.com/c/1991969 I added a new, faster way to disable
> ARB_texture_rectangle support in ANGLE's shader translator. This change
> starts using it in Chrome, replacing the earlier change introduced in
> https://crrev.com/c/1842223
> 
> Bug: angleproject:3770
> Change-Id: Ica718828581b49efc34230f9f53f28fdec77eb67
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1992548
> Commit-Queue: James Darpinian <jdarpinian@chromium.org>
> Reviewed-by: Kenneth Russell <kbr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#732221}

TBR=geofflang@chromium.org,kbr@chromium.org,jdarpinian@chromium.org

Change-Id: If28e90472d21c3f3f1dbfb01abdd8102dc413258
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:3770
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2003030
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732477}

gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc

@@ -1198,14 +1198,6 @@ gpu::ContextResult GLES2DecoderPassthroughImpl::Initialize(
   api()->glGetIntegervFn(GL_SCISSOR_BOX, scissor_);
   ApplySurfaceDrawOffset();
 
-#if defined(OS_MACOSX)
-  // On mac we need the ANGLE_texture_rectangle extension to support IOSurface
-  // backbuffers, but we don't want it exposed to WebGL user shaders. This
-  // disables support for it in the shader compiler.
-  if (feature_info_->IsWebGLContext())
-    api()->glDisableFn(GL_TEXTURE_RECTANGLE_ANGLE);
-#endif
-
   set_initialized();
   return gpu::ContextResult::kSuccess;
 }

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc

@@ -8,6 +8,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/numerics/ranges.h"
 #include "base/strings/string_number_conversions.h"
+#include "build/build_config.h"
 #include "gpu/command_buffer/common/discardable_handle.h"
 #include "gpu/command_buffer/service/decoder_client.h"
 #include "gpu/command_buffer/service/gl_stream_texture_image.h"
@@ -708,7 +709,18 @@ error::Error GLES2DecoderPassthroughImpl::DoColorMask(GLboolean red,
 }
 
 error::Error GLES2DecoderPassthroughImpl::DoCompileShader(GLuint shader) {
+#if defined(OS_MACOSX)
+  // On mac we need this extension to support IOSurface backbuffers, but we
+  // don't want it exposed to WebGL user shaders. Temporarily disable it during
+  // shader compilation.
+  if (feature_info_->IsWebGLContext())
+    api()->glDisableExtensionANGLEFn("GL_ANGLE_texture_rectangle");
+#endif
   api()->glCompileShaderFn(GetShaderServiceID(shader, resources_));
+#if defined(OS_MACOSX)
+  if (feature_info_->IsWebGLContext())
+    api()->glRequestExtensionANGLEFn("GL_ANGLE_texture_rectangle");
+#endif
   return error::kNoError;
 }
 

ui/gl/gl_bindings.h

@@ -84,12 +84,6 @@
 #define GL_TEXTURE_BINDING_EXTERNAL_OES                  0x8D67
 #define GL_REQUIRED_TEXTURE_IMAGE_UNITS_OES              0x8D68
 
-// GL_ANGLE_texture_rectangle
-#define GL_MAX_RECTANGLE_TEXTURE_SIZE_ANGLE 0x84F8
-#define GL_TEXTURE_RECTANGLE_ANGLE 0x84F5
-#define GL_TEXTURE_BINDING_RECTANGLE_ANGLE 0x84F6
-#define GL_SAMPLER_2D_RECT_ANGLE 0x8B63
-
 // GL_ANGLE_translated_shader_source
 #define GL_TRANSLATED_SHADER_SOURCE_LENGTH_ANGLE         0x93A0