Revert of Add gamma/sRGB tag to SkImageInfo (patchset #1 id:1 of https://codereview.chromium.org/527073003/)

Reason for revert:
virtual gpu failures in layouttests

http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/23717

[6:6:0903/041147:1700960503:INFO:SkBitmap.cpp(1003)] ../../third_party/skia/src/core/SkBitmap.cpp:1003: failed assertion "fPixelRef->info() == pixelRef->info()"

[6:6:0903/041147:1700961002:FATAL:SkBitmap.cpp(1003)] SK_CRASH
#0 0x7f9867df2c1e base::debug::StackTrace::StackTrace()
#1 0x7f9867e89e05 logging::LogMessage::~LogMessage()
#2 0x7f98689c4970 SkDebugf_FileLine()
#3 0x7f986870ebc6 SkBitmap::deepCopyTo()
#4 0x7f98690a3b6d blink::deepSkBitmapCopy()
#5 0x7f98690a3abe blink::ImageBuffer::copyImage()
#6 0x7f985fd4479e blink::ImageBitmap::ImageBitmap()
#7 0x7f985fd45942 blink::ImageBitmap::create()
#8 0x7f985fd84fdc blink::ImageBitmapFactories::createImageBitmap()
#9 0x7f985fd84d11 blink::ImageBitmapFactories::createImageBitmap()
#10 0x7f985ec9a7f2 blink::LocalDOMWindowV8Internal::createImageBitmap13Method()
#11 0x7f985ec96b0c blink::LocalDOMWindowV8Internal::createImageBitmapMethod()
#12 0x7f985ec91954 blink::LocalDOMWindowV8Internal::createImageBitmapMethodCallback()
#13 0x7f9869955af0 v8::internal::FunctionCallbackArguments::Call()
#14 0x7f98699833bd v8::internal::Builtin_HandleApiCall()

Original issue's description:
> Add gamma/sRGB tag to SkImageInfo
>
> This reverts commit 1cbc68f9659f15206d920dacd434ddf4b658ad1f.
>
> requires this to land in blink https://codereview.chromium.org/531883002/
>
> Committed: https://skia.googlesource.com/skia/+/2f6abdecc5c2f21da13003c615903679abc73fc7

R=fmalita@google.com, reed@chromium.org
TBR=fmalita@google.com, reed@chromium.org
NOTREECHECKS=true
NOTRY=true

Author: reed@google.com

Review URL: https://codereview.chromium.org/535113002

1 files changed, 21 insertions, 111 deletions

diff --git a/src/core/SkImageInfo.cpp b/src/core/SkImageInfo.cpp
index 44fd808dc8..e61cd7d45f 100644
--- a/src/core/SkImageInfo.cpp
+++ b/src/core/SkImageInfo.cpp
@@ -9,53 +9,34 @@
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 
-static bool color_type_supports_sRGB(SkColorType colorType) {
-    switch (colorType) {
-        case kRGBA_8888_SkColorType:
-        case kBGRA_8888_SkColorType:
-            return true;
-        default:
-            return false;
-    }
+static bool alpha_type_is_valid(SkAlphaType alphaType) {
+    return (alphaType >= 0) && (alphaType <= kLastEnum_SkAlphaType);
 }
 
-static bool color_type_supports_gamma(SkColorType colorType) {
-    switch (colorType) {
-        case kRGBA_8888_SkColorType:
-        case kBGRA_8888_SkColorType:
-        // case kLuminance ...
-            return true;
-        default:
-            return false;
-    }
+static bool color_type_is_valid(SkColorType colorType) {
+    return (colorType >= 0) && (colorType <= kLastEnum_SkColorType);
 }
 
-static float pin_gamma_to_legal(float gamma) {
-    if (!SkScalarIsFinite(gamma)) {
-        return 1;
-    }
-    // these limits are just made up -- feel free to change them within reason
-    const float min_gamma = 0.01f;
-    const float max_gamma = 4.0;
-    return SkScalarPin(gamma, min_gamma, max_gamma);
-}
+void SkImageInfo::unflatten(SkReadBuffer& buffer) {
+    fWidth = buffer.read32();
+    fHeight = buffer.read32();
 
-SkImageInfo SkImageInfo::MakeSRGB(int width, int height, SkColorType ct, SkAlphaType at) {
-    Profile p = color_type_supports_sRGB(ct) ? kSRGB_Profile : kUnknown_Profile;
-    return SkImageInfo(width, height, ct, at, p, 0);
+    uint32_t packed = buffer.read32();
+    SkASSERT(0 == (packed >> 16));
+    fAlphaType = (SkAlphaType)((packed >> 8) & 0xFF);
+    fColorType = (SkColorType)((packed >> 0) & 0xFF);
+    buffer.validate(alpha_type_is_valid(fAlphaType) &&
+                    color_type_is_valid(fColorType));
 }
 
-SkImageInfo SkImageInfo::MakeWithGamma(int width, int height, SkColorType ct, SkAlphaType at,
-                                       float gamma) {
-    Profile p;
-    if (color_type_supports_gamma(ct)) {
-        gamma = pin_gamma_to_legal(gamma);
-        p = kExponential_Profile;
-    } else {
-        p = kUnknown_Profile;
-        gamma = 0;
-    }
-    return SkImageInfo(width, height, ct, at, p, gamma);
+void SkImageInfo::flatten(SkWriteBuffer& buffer) const {
+    buffer.write32(fWidth);
+    buffer.write32(fHeight);
+
+    SkASSERT(0 == (fAlphaType & ~0xFF));
+    SkASSERT(0 == (fColorType & ~0xFF));
+    uint32_t packed = (fAlphaType << 8) | fColorType;
+    buffer.write32(packed);
 }
 
 bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
@@ -88,74 +69,3 @@ bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
     }
     return true;
 }
-
-void SkImageInfo::unflatten(SkReadBuffer& buffer) {
-    *this = Unflatten(buffer);
-}
-
-////////////////////////////////////////////////////////////////////////////////////////////
-
-static bool alpha_type_is_valid(SkAlphaType alphaType) {
-    return (alphaType >= 0) && (alphaType <= kLastEnum_SkAlphaType);
-}
-
-static bool color_type_is_valid(SkColorType colorType) {
-    return (colorType >= 0) && (colorType <= kLastEnum_SkColorType);
-}
-
-static float igamma_to_gamma(int gamma3dot9) {
-    return gamma3dot9 / 512.0f;
-}
-
-static unsigned gamma_to_igamma(float gamma) {
-    SkASSERT(gamma >= 0 && gamma < 8);
-    int igamma = SkScalarRoundToInt(gamma * 512);
-    SkASSERT(igamma >= 0 && igamma <= 0xFFF);
-    return igamma;
-}
-
-SkImageInfo SkImageInfo::Unflatten(SkReadBuffer& buffer) {
-    int width = buffer.read32();
-    int height = buffer.read32();
-    uint32_t packed = buffer.read32();
-    
-    SkColorType ct = (SkColorType)((packed >> 0) & 0xFF);   // 8 bits for colortype
-    SkAlphaType at = (SkAlphaType)((packed >> 8) & 0xFF);   // 8 bits for alphatype
-    if (!alpha_type_is_valid(at) || !color_type_is_valid(ct)) {
-        return MakeUnknown();
-    }
-
-    // Earlier formats always stored 0 in the upper 16 bits. That corresponds to
-    // days before we had gamma/profile. That happens to correspond to kUnknown_Profile,
-    // which means we can just ignore the gamma value anyways.
-    //
-    int iprofile = ((packed >> 16) & 0xF);  // 4 bits for profile
-    
-    switch (iprofile) {
-        case kUnknown_Profile:
-            return Make(width, height, ct, at);
-        case kSRGB_Profile:
-            return MakeSRGB(width, height, ct, at);
-        case kExponential_Profile: {
-            int igamma = packed >> 20;      // 12 bits for gamma 3.9
-            float gamma = igamma_to_gamma(igamma);
-            return MakeWithGamma(width, height, ct, at, gamma);
-        }
-        default:
-            (void)buffer.validate(false);
-            return MakeUnknown();
-    }
-}
-
-void SkImageInfo::flatten(SkWriteBuffer& buffer) const {
-    buffer.write32(fWidth);
-    buffer.write32(fHeight);
-    
-    SkASSERT(0 == (fColorType & ~0xFF));    // 8 bits for colortype
-    SkASSERT(0 == (fAlphaType & ~0xFF));    // 8 bits for alphatype
-    SkASSERT(0 == (fProfile & ~0xF));       // 4 bits for profile
-    int igamma = gamma_to_igamma(fGamma);   // 12 bits for gamma (if needed)
- 
-    uint32_t packed = (igamma << 20) | (fProfile << 16) | (fAlphaType << 8) | fColorType;
-    buffer.write32(packed);
-}