Revert of Add compositor support for half-float RGBA buffers and textures

cc/resources/resource_format.cc

Index: cc/resources/resource_format.cc
diff --git a/cc/resources/resource_format.cc b/cc/resources/resource_format.cc
index a7db8a780823461b560942dee98a6f581eda4041..2d139ab5c0465e910b289844893c6acb63a3653f 100644
--- a/cc/resources/resource_format.cc
+++ b/cc/resources/resource_format.cc
@@ -12,8 +12,6 @@
 
 int BitsPerPixel(ResourceFormat format) {
   switch (format) {
-    case RGBA_F16:
-      return 64;
     case BGRA_8888:
     case RGBA_8888:
       return 32;
@@ -44,7 +42,6 @@
       GL_UNSIGNED_BYTE,           // ETC1
       GL_UNSIGNED_BYTE,           // RED_8
       GL_HALF_FLOAT_OES,          // LUMINANCE_F16
-      GL_HALF_FLOAT_OES,          // RGBA_F16
   };
   static_assert(arraysize(format_gl_data_type) == (RESOURCE_FORMAT_MAX + 1),
                 "format_gl_data_type does not handle all cases.");
@@ -64,7 +61,6 @@
       GL_ETC1_RGB8_OES,  // ETC1
       GL_RED_EXT,        // RED_8
       GL_LUMINANCE,      // LUMINANCE_F16
-      GL_RGBA,           // RGBA_F16
   };
   static_assert(arraysize(format_gl_data_format) == (RESOURCE_FORMAT_MAX + 1),
                 "format_gl_data_format does not handle all cases.");
@@ -95,7 +91,6 @@
       GL_RGB,        // ETC1
       GL_LUMINANCE,  // RED_8
       GL_LUMINANCE,  // LUMINANCE_F16
-      GL_RGBA,       // RGBA_F16
   };
   static_assert(arraysize(format_gl_data_format) == (RESOURCE_FORMAT_MAX + 1),
                 "format_gl_data_format does not handle all cases.");
@@ -118,7 +113,6 @@
     case LUMINANCE_8:
     case RGB_565:
     case LUMINANCE_F16:
-    case RGBA_F16:
       break;
   }
   NOTREACHED();
@@ -135,7 +129,6 @@
     case RGBA_8888:
     case BGRA_8888:
     case ALPHA_8:
-    case RGBA_F16:
       return true;
     case LUMINANCE_8:
     case RGB_565: