resolve merge conflicts of 8e50e696 to master

BUG: None
Test: I solemnly swear I tested this conflict resolution.
Change-Id: I82ca39c5d7b8316450e714d5282552a300f59e9b
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
index 08cd5b0..64095dd 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
@@ -259,10 +259,8 @@
     mState.setTexture(texture);
 }
 
-mat4 GLES20RenderEngine::setupColorTransform(const mat4& colorTransform) {
-    mat4 oldTransform = mState.getColorMatrix();
+void GLES20RenderEngine::setupColorTransform(const mat4& colorTransform) {
     mState.setColorMatrix(colorTransform);
-    return oldTransform;
 }
 
 void GLES20RenderEngine::disableTexturing() {
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
index 9acd79b..c9e402d 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
@@ -80,7 +80,7 @@
     virtual void setupLayerTexturing(const Texture& texture);
     virtual void setupLayerBlackedOut();
     virtual void setupFillWithColor(float r, float g, float b, float a);
-    virtual mat4 setupColorTransform(const mat4& colorTransform);
+    virtual void setupColorTransform(const mat4& colorTransform);
     virtual void disableTexturing();
     virtual void disableBlending();
 
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.h b/services/surfaceflinger/RenderEngine/RenderEngine.h
index df9e6a7..d559464 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.h
@@ -112,7 +112,7 @@
     virtual void setupLayerBlackedOut() = 0;
     virtual void setupFillWithColor(float r, float g, float b, float a) = 0;
 
-    virtual mat4 setupColorTransform(const mat4& /* colorTransform */) = 0;
+    virtual void setupColorTransform(const mat4& /* colorTransform */) = 0;
 
     virtual void disableTexturing() = 0;
     virtual void disableBlending() = 0;
@@ -224,7 +224,7 @@
 
     void checkErrors() const override;
 
-    mat4 setupColorTransform(const mat4& /* colorTransform */) override { return mat4(); }
+    void setupColorTransform(const mat4& /* colorTransform */) override {}
 
     // internal to RenderEngine
     EGLDisplay getEGLDisplay() const;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index b581bb8..cb2172b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2964,18 +2964,13 @@
     const DisplayRenderArea renderArea(displayDevice);
     const auto hwcId = displayDevice->getHwcDisplayId();
     const bool hasClientComposition = getBE().mHwc->hasClientComposition(hwcId);
-    const bool hasDeviceComposition = getBE().mHwc->hasDeviceComposition(hwcId);
-    const bool skipClientColorTransform = getBE().mHwc->hasCapability(
-        HWC2::Capability::SkipClientColorTransform);
     ATRACE_INT("hasClientComposition", hasClientComposition);
 
-    mat4 oldColorMatrix;
-    mat4 legacySrgbSaturationMatrix = mLegacySrgbSaturationMatrix;
-    const bool applyColorMatrix = !hasDeviceComposition && !skipClientColorTransform;
-    if (applyColorMatrix) {
-        oldColorMatrix = getRenderEngine().setupColorTransform(mDrawingState.colorMatrix);
-        legacySrgbSaturationMatrix = mDrawingState.colorMatrix * legacySrgbSaturationMatrix;
-    }
+    bool applyColorMatrix = false;
+    bool applyLegacyColorMatrix = false;
+    mat4 colorMatrix;
+    mat4 legacyColorMatrix;
+    const mat4* currentColorMatrix = nullptr;
 
     if (hasClientComposition) {
         ALOGV("hasClientComposition");
@@ -2988,6 +2983,24 @@
         getBE().mRenderEngine->setDisplayMaxLuminance(
                 displayDevice->getHdrCapabilities().getDesiredMaxLuminance());
 
+        const bool hasDeviceComposition = getBE().mHwc->hasDeviceComposition(hwcId);
+        const bool skipClientColorTransform = getBE().mHwc->hasCapability(
+            HWC2::Capability::SkipClientColorTransform);
+
+        applyColorMatrix = !hasDeviceComposition && !skipClientColorTransform;
+        if (applyColorMatrix) {
+            colorMatrix = mDrawingState.colorMatrix;
+        }
+
+        applyLegacyColorMatrix = mDisplayColorSetting == DisplayColorSetting::ENHANCED;
+        if (applyLegacyColorMatrix) {
+            if (applyColorMatrix) {
+                legacyColorMatrix = colorMatrix * mLegacySrgbSaturationMatrix;
+            } else {
+                legacyColorMatrix = mLegacySrgbSaturationMatrix;
+            }
+        }
+
         if (!displayDevice->makeCurrent()) {
             ALOGW("DisplayDevice::makeCurrent failed. Aborting surface composition for display %s",
                   displayDevice->getDisplayName().c_str());
@@ -3073,22 +3086,22 @@
                     break;
                 }
                 case HWC2::Composition::Client: {
-                    // Only apply saturation matrix layer that is legacy SRGB dataspace
-                    // when auto color mode is on.
-                    bool restore = false;
-                    mat4 savedMatrix;
-                    if (mDisplayColorSetting == DisplayColorSetting::ENHANCED &&
-                        layer->isLegacyDataSpace()) {
+                    // switch color matrices lazily
+                    if (layer->isLegacyDataSpace()) {
                         // TODO(b/78891890) Legacy sRGB saturation matrix should be set
                         // separately.
-                        savedMatrix =
-                            getRenderEngine().setupColorTransform(legacySrgbSaturationMatrix);
-                        restore = true;
+                        if (applyLegacyColorMatrix && currentColorMatrix != &legacyColorMatrix) {
+                            getRenderEngine().setupColorTransform(legacyColorMatrix);
+                            currentColorMatrix = &legacyColorMatrix;
+                        }
+                    } else {
+                        if (applyColorMatrix && currentColorMatrix != &colorMatrix) {
+                            getRenderEngine().setupColorTransform(colorMatrix);
+                            currentColorMatrix = &colorMatrix;
+                        }
                     }
+
                     layer->draw(renderArea, clip);
-                    if (restore) {
-                        getRenderEngine().setupColorTransform(savedMatrix);
-                    }
                     break;
                 }
                 default:
@@ -3100,8 +3113,8 @@
         firstLayer = false;
     }
 
-    if (applyColorMatrix) {
-        getRenderEngine().setupColorTransform(oldColorMatrix);
+    if (applyColorMatrix || applyLegacyColorMatrix) {
+        getRenderEngine().setupColorTransform(mat4());
     }
 
     // disable scissor at the end of the frame
diff --git a/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h b/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h
index 29cd2d5..93769a5 100644
--- a/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h
+++ b/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h
@@ -60,7 +60,7 @@
     MOCK_METHOD1(setupLayerTexturing, void(const Texture&));
     MOCK_METHOD0(setupLayerBlackedOut, void());
     MOCK_METHOD4(setupFillWithColor, void(float, float, float, float));
-    MOCK_METHOD1(setupColorTransform, mat4(const mat4&));
+    MOCK_METHOD1(setupColorTransform, void(const mat4&));
     MOCK_METHOD0(disableTexturing, void());
     MOCK_METHOD0(disableBlending, void());
     MOCK_METHOD1(setSourceY410BT2020, void(bool));